From 60ad747e32b3d92c2a82b99dc5922db37a076010 Mon Sep 17 00:00:00 2001
From: Andy Kopra <ack@acm.org>
Date: Sun, 18 Oct 2026 20:22:13 +0200
Subject: [PATCH] Everyone has the same buttons; the view is personal

The host's rights and the co-host are gone: anyone in a session may
start a new page, put an image on the page, load a kept page, hide,
expand and shrink, and move or remove images and Hides; the page left
is kept in every notebook.  Fit and Normal scale act on your own screen
only.  A session goes on without whoever started it, and a newcomer to
an empty room starts page 1 with New.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---
 README.md                |  14 +--
 client/index.html        |  14 +--
 client/js/chooser.js     |  16 +--
 client/js/crypto.js      |   5 +-
 client/js/main.js        | 114 ++++++--------------
 client/js/page_file.js   |   2 +-
 client/js/page_model.js  |  15 +--
 client/js/session.js     | 167 +++++++----------------------
 client/kokkoja.css       |   2 -
 tests/test_end_to_end.py | 220 ++++++++++++++++++++-------------------
 10 files changed, 215 insertions(+), 354 deletions(-)

diff --git a/README.md b/README.md
index 7ac434b..4bf2c7e 100644
--- a/README.md
+++ b/README.md
@@ -13,24 +13,24 @@ may be used.
 
 ## Documentation
 
-The user documentation (an introduction, Kokkoja in five minutes, a
-guest's Kokkoja, a host's Kokkoja, and how Kokkoja works) is being moved
+The user documentation (an introduction, Kokkoja in five minutes,
+using Kokkoja, and how Kokkoja works) is being moved
 to a new format and is not in this repository at the moment.  It will
 return with a later release.
 
 ## In short
 
-A guest needs nothing but a web browser: open the invitation link, enter
-a name, join.  A host can start a session from the same web site,
+Joining needs nothing but a web browser: open the invitation link, enter
+a name, join.  Anyone can start a session from the same web site,
 `https://app.kokkoja.com/`, with the notebooks kept in the
-browser.
+browser; everyone in a session has the same buttons.
 
-A host who wants notebooks as files needs Python 3 and this directory:
+Whoever wants notebooks as files needs Python 3 and this directory:
 
     python3 kokkoja.py --relay wss://app.kokkoja.com/relay
 
 opens Kokkoja in the browser; *Start a session* gives an invitation to
-send to the guests.  Notebooks are directories in `Kokkoja` in the
+send to the others.  Notebooks are directories in `Kokkoja` in the
 Documents directory.
 
 ## What is here
diff --git a/client/index.html b/client/index.html
index 3df62de..2d8235f 100644
--- a/client/index.html
+++ b/client/index.html
@@ -82,12 +82,12 @@
     </div>
     </div>
     <div class="group after_settings" role="radiogroup" aria-label="Hide, Arrange and Eraser">
-      <button type="button" data-tool="hide" aria-pressed="false" hidden
+      <button type="button" data-tool="hide" aria-pressed="false"
               data-help="Hide part of the page for everyone: drag open a rectangle, and what lies under it is covered in white, marked by blue corners. Rest the pen on it to move it, or near a corner to resize it, or use Arrange; a tap of the eraser removes it.">Hide</button>
       <button type="button" data-tool="arrange" aria-pressed="false"
               data-help="Move and resize: the corners of every image are marked in blue, as those of Hides and text rectangles always are. Drag inside an image, a Hide or a text rectangle of yours to move it, drag a corner to resize it (an image keeps its shape). A press elsewhere does nothing. With any other tool, resting the pen on one of them for half a second does the same.">Arrange</button>
       <button type="button" data-tool="eraser" aria-pressed="false"
-              data-help="Erase your own strokes and text by moving over them. A tap on an image, or on a Hide rectangle, removes it, if you are the host or a co-host (or added the image yourself). Two quick taps on empty paper, away from anything the eraser would remove, undo your latest mark; again, and the one before.">Eraser</button>
+              data-help="Erase your own strokes and text by moving over them. A tap on an image, or on a Hide rectangle, removes it for everyone. Two quick taps on empty paper, away from anything the eraser would remove, undo your latest mark; again, and the one before.">Eraser</button>
     </div>
       <button id="undo" type="button" disabled
               data-help="Take back your latest mark: a stroke, an erasure, a text block typed or moved, a Hide rectangle. Again for the one before. Also Ctrl+Z (Command+Z on a Mac), or two quick taps of the eraser on empty paper. Only your own marks, and only on this page since you opened it.">Undo</button>
@@ -99,14 +99,14 @@
       <div id="page_menu" class="popup menu" role="menu" hidden>
         <div class="menu_title">Change the display of the page</div>
         <button id="zoom_fit" type="button" class="menu_item" role="menuitem"
-                data-help="Show the whole page in the window. Pressed by the host, it does so on every screen. Ctrl (Command on a Mac) with the scroll wheel, or with a pen stroke up or down, zooms about the pointer.">Fit to the window</button>
+                data-help="Show the whole page in the window, on your screen only. Ctrl (Command on a Mac) with the scroll wheel, or with a pen stroke up or down, zooms about the pointer.">Fit to the window</button>
         <button id="zoom_sheet" type="button" class="menu_item" role="menuitem"
-                data-help="Show the page at the scale a new page has, one full page filling the window. A shrunk page is then seen at its own size rather than enlarged. Pressed by the host, it does so on every screen.">Normal scale</button>
+                data-help="Show the page at the scale a new page has, one full page filling the window. A shrunk page is then seen at its own size rather than enlarged. On your screen only.">Normal scale</button>
         <hr>
         <div class="menu_title">Change the size of the page</div>
-        <button id="zoom_expand" type="button" class="menu_item" role="menuitem" hidden
+        <button id="zoom_expand" type="button" class="menu_item" role="menuitem"
                 data-help="Make the page fill the window, for everyone, at this zoom, in both directions. Nothing on it moves.">Expand to the window</button>
-        <button id="zoom_shrink" type="button" class="menu_item" role="menuitem" hidden
+        <button id="zoom_shrink" type="button" class="menu_item" role="menuitem"
                 data-help="Make the page, for everyone, just large enough for what is on it, with the margin around. Nothing on it moves.">Shrink to the contents</button>
         <hr>
         <label class="menu_item toggle" role="menuitemcheckbox"
@@ -119,7 +119,7 @@
       <button id="load_image" type="button"
               data-help="Put an image file, such as a scanned exercise, on the page for everyone: below the images already there, centred, at its own size. Rest the pen on an image to move it, or near a corner to scale it; it comes to the front. A tap of the eraser on an image removes it; writing on it stays.">Image</button>
       <button id="load_notebook_page" type="button"
-              data-help="Your notebooks and the pages kept in them, to look at or to delete. The host and co-hosts can start a new page for everyone from a kept page, with everything on it; the current page is then kept in each notebook.">Notebooks</button>
+              data-help="Your notebooks and the pages kept in them, to look at or to delete. A kept page starts a new page for everyone, with everything on it; the current page is then kept in each notebook.">Notebooks</button>
     </div>
     <div class="group" aria-label="Notebook">
       <select id="session_notebook" class="notebook_pick" aria-label="Current notebook"
diff --git a/client/js/chooser.js b/client/js/chooser.js
index 3bc1448..14c5180 100644
--- a/client/js/chooser.js
+++ b/client/js/chooser.js
@@ -15,10 +15,9 @@
  * a Trash the entries are moved there, and the button says so;
  * in the browser they are gone for good, and the button says that.  The
  * notebook being written in cannot be marked: its mark explains.
- * Everyone has the chooser (Andy, 2026-10-11), so that a guest can see
- * and clear what their notebook holds, in a browser above all; loading
- * a page into the session is for the host and co-hosts, and a card says
- * so to anyone else.
+ * Everyone has the chooser (Andy, 2026-10-11), so that anyone can see
+ * and clear what their notebook holds, in a browser above all, and
+ * since 2026-10-18 anyone may load a page into the session from it.
  */
 
 import {
@@ -163,7 +162,6 @@ export class NotebookChooser {
     /** The notebook being written in, which cannot be deleted while it is. */
     this.writing = '';
     /** Whether this participant may load a page into the session. */
-    this.mayLoad = true;
     /** Whether deletions go to a Trash (the local program's) or are for good. */
     this.trash = false;
     /** Counts openings, so that pictures fetched for an earlier one are dropped. */
@@ -188,12 +186,10 @@ export class NotebookChooser {
   /**
    * Show the notebooks, or the pages of the only notebook.
    * @param {string} [notebook]  Open on this notebook: the one being written in.
-   * @param {boolean} [mayLoad]  Whether a page may be loaded into the session.
    */
-  async open(notebook, mayLoad = true) {
+  async open(notebook) {
     this.opening += 1;
     this.writing = notebook ?? '';
-    this.mayLoad = mayLoad;
     this.clearMarks();
     this.dialog.showModal();
     element('chooser_message').textContent = '';
@@ -289,10 +285,6 @@ export class NotebookChooser {
       title.textContent = pageTitle(pageName);
       card.append(picture, title);
       card.addEventListener('click', async () => {
-        if (!this.mayLoad) {
-          this.say('Only the host and co-hosts can start a page for everyone from a kept page.');
-          return;
-        }
         const text = await readPage(notebook, pageName);
         if (text === null) return;
         this.dialog.close();
diff --git a/client/js/crypto.js b/client/js/crypto.js
index 5681579..4a95da7 100644
--- a/client/js/crypto.js
+++ b/client/js/crypto.js
@@ -83,7 +83,10 @@ export function randomId(byteCount = 9) {
  * @typedef {object} Invitation
  * @property {string} relay   Address of the relay, ws:// or wss://.
  * @property {string} secret  The session secret.
- * @property {string} hostId  Participant id of the host.
+ * @property {string} hostId  Participant id of whoever started the
+ *     session (named the host until 2026-10-18; the field keeps its name
+ *     so that invitations and page files are unchanged).  It gives no
+ *     right.
  */
 
 /**
diff --git a/client/js/main.js b/client/js/main.js
index 06afbdf..955fb10 100644
--- a/client/js/main.js
+++ b/client/js/main.js
@@ -230,7 +230,7 @@ const CONNECTION_GRACE_MS = 1500;
  * The notice line between the toolbar and the page.  It says nothing
  * while all is well.  A STANDING notice, kept by its source until that
  * source clears it, is a state: not connected, the page not being
- * saved, no page from the host yet.  A PASSING notice is a report of
+ * saved, no page from the others yet.  A PASSING notice is a report of
  * one event, kept for a few seconds: a page kept or exported, a file
  * that was not an image.  Standing notices come before a passing one.
  */
@@ -470,7 +470,6 @@ async function enterSession(invitationText, name, notebook) {
   input('invitation').value = config.site ? formatInvitationLink(config.site, plainInvitation) : plainInvitation;
   showInvitationCode(config.site ? input('invitation').value : '');
 
-  const isHost = identity.id === invitation.hostId;
   let tool = /** @type {Tool} */ ('pen');
   /** The Shape tool's current shape, remembered in this browser (Andy, 2026-10-14). */
   let shape = shapeNamed(localStorage.getItem(SHAPE_KEY));
@@ -501,7 +500,7 @@ async function enterSession(invitationText, name, notebook) {
   function showPageNumber() {
     const waiting = session.page.number === 0;
     element('page_number').textContent = waiting ? 'No page yet' : `Page ${session.page.number}`;
-    standingNotice('page', waiting ? 'Waiting for the host’s page' : '', false);
+    standingNotice('page', waiting ? 'Waiting for the others’ page; New starts one' : '', false);
   }
   /** @type {ReturnType<typeof setTimeout> | undefined} */
   let connectionNoticeTimer;
@@ -568,18 +567,6 @@ async function enterSession(invitationText, name, notebook) {
         textEditor?.layout();
         writer.changed();
       },
-      onViewCommand: (command) => {
-        log(`The host's view: ${command === 'fit' ? 'Fit' : 'Normal scale'}`);
-        if (command === 'fit') renderer.fit();
-        else renderer.sheetScale();
-      },
-      onPermissionsChanged: () => {
-        log(`May start pages: ${session.mayMakePages() ? 'yes' : 'no'}` +
-            (session.isHost ? `; guests allowed: ${session.permitted.size}` : ''));
-        showHostTools();
-        showParticipants(session, renderer);
-        refreshArrangeCues();
-      },
       onParticipantsChanged: () => {
         syncLayers();
         showParticipants(session, renderer);
@@ -846,12 +833,11 @@ async function enterSession(invitationText, name, notebook) {
   /**
    * With the Arrange tool chosen, mark everything a press can move or
    * resize with a blue box and corners (Andy, 2026-10-14): the images
-   * and Hides for the host and co-hosts, one's own text blocks and
-   * shapes; free text, which has no width to resize, gets the box without
-   * the corners.  The one being held is left out, the green grip standing
-   * in its place until the pointer lifts.  Called whenever the images,
-   * the Hides, one's own text or shapes, the right, or the hold may have
-   * changed.
+   * and Hides, one's own text blocks and shapes; free text, which has
+   * no width to resize, gets the box without the corners.  The one being
+   * held is left out, the green grip standing in its place until the
+   * pointer lifts.  Called whenever the images, the Hides, one's own
+   * text or shapes, or the hold may have changed.
    */
   function refreshArrangeCues() {
     if (tool !== 'arrange') {
@@ -861,16 +847,14 @@ async function enterSession(invitationText, name, notebook) {
     /** @type {{rect: import('./page_model.js').Rectangle, kind: 'image' | 'text' | 'hide' | 'shape' | 'stroke', corners: boolean}[]} */
     const cues = [];
     const page = session.page;
-    if (session.mayMakePages()) {
-      page.images.forEach((im, index) => {
-        if (held?.kind === 'image' && held.index === index) return;
-        cues.push({ kind: 'image', rect: { left: im.x, top: im.y, width: im.width, height: im.height }, corners: true });
-      });
-      page.hides.forEach((h, index) => {
-        if (held?.kind === 'hide' && held.index === index) return;
-        cues.push({ kind: 'hide', rect: { left: h.x, top: h.y, width: h.width, height: h.height }, corners: true });
-      });
-    }
+    page.images.forEach((im, index) => {
+      if (held?.kind === 'image' && held.index === index) return;
+      cues.push({ kind: 'image', rect: { left: im.x, top: im.y, width: im.width, height: im.height }, corners: true });
+    });
+    page.hides.forEach((h, index) => {
+      if (held?.kind === 'hide' && held.index === index) return;
+      cues.push({ kind: 'hide', rect: { left: h.x, top: h.y, width: h.width, height: h.height }, corners: true });
+    });
     for (const block of session.ownLayer.texts.values()) {
       if (held?.kind === 'text' && held.id === block.id) continue;
       cues.push({ kind: 'text', rect: textBounds(block), corners: block.height !== null });
@@ -1110,13 +1094,13 @@ async function enterSession(invitationText, name, notebook) {
     if (rects.length) return rects;
     const page = session.page;
     const hide = page.hideAt(x, y, 0);
-    if (hide && session.mayMakePages()) {
+    if (hide) {
       const h = page.hides[hide.index];
       return [{ left: h.x, top: h.y, width: h.width, height: h.height }];
     }
     const found = page.imageAt(x, y, 0);
     const image = found && page.images[found.index];
-    if (image && (session.mayMakePages() || image.by === session.identity.id)) {
+    if (image) {
       return [{ left: image.x, top: image.y, width: image.width, height: image.height }];
     }
     return [];
@@ -1143,15 +1127,15 @@ async function enterSession(invitationText, name, notebook) {
     zoomTo: (pixelsUp) => renderer.zoomDragTo(pixelsUp),
     endZoom: () => renderer.endZoomDrag(),
     // A hold moves what is under the pen, or resizes it from a corner: a
-    // Hide rectangle or an image (for the host and co-hosts), or a
-    // text block of our own.  The dot drawn meanwhile goes.
+    // Hide rectangle, an image, or a text block of our own.  The dot
+    // drawn meanwhile goes.
     beginHold: (clientX, clientY) => {
       const [x, y] = renderer.pageFromClient(clientX, clientY);
       const reach = renderer.cornerReach();
       const page = session.page;
       /** @type {Held | null} */
       let found = null;
-      const hide = session.mayMakePages() ? page.hideAt(x, y, reach) : null;
+      const hide = page.hideAt(x, y, reach);
       if (hide) {
         const h = page.hides[hide.index];
         found = hold('hide', hide.index, h.id, { left: h.x, top: h.y, width: h.width, height: h.height }, hide.corner, x, y);
@@ -1190,7 +1174,7 @@ async function enterSession(invitationText, name, notebook) {
           const stroke = shapes[shapeAt.index];
           const box = /** @type {import('./page_model.js').Rectangle} */ (strokeBox(stroke));
           if (session.beginShapeEdit(stroke.id)) found = hold('shape', shapeAt.index, stroke.id, box, shapeAt.corner, x, y);
-        } else if (session.mayMakePages()) {
+        } else {
           const image = page.imageAt(x, y, reach);
           if (image) {
             const index = session.raiseImage(image.index);
@@ -1277,8 +1261,8 @@ async function enterSession(invitationText, name, notebook) {
         lastEmptyTap = 0;
         return;
       }
-      // A tap of the eraser on a Hide rectangle or an image removes it
-      // (the right to make pages, or having added the image).
+      // A tap of the eraser on a Hide rectangle or an image removes it,
+      // for everyone (by anyone since 2026-10-18).
       let took = erased.strokes + erased.texts > 0;
       if (!took) {
         const hide = session.page.hideAt(x, y, 0);
@@ -1458,8 +1442,8 @@ async function enterSession(invitationText, name, notebook) {
     textEditor?.layout();
     viewChanged();
   };
-  // The host's Fit and Normal scale ("A4" until 2026-10-14) reach everyone (Andy, 2026-10-08); a guest's
-  // are the guest's own.
+  // Fit and Normal scale ("A4" until 2026-10-14) are each person's own
+  // (2026-10-18; the host's reached everyone from 2026-10-08 until then).
   // The page and view commands live in the Page menu (Andy, 2026-10-14:
   // seldom used, and the one row is precious).
   attachPopup(element('page_menu_button'), element('page_menu'));
@@ -1505,14 +1489,8 @@ async function enterSession(invitationText, name, notebook) {
       log(`The manual could not be copied: ${error}`);
     }
   });
-  element('zoom_fit').addEventListener('click', () => {
-    renderer.fit();
-    session.sendViewCommand('fit');
-  });
-  element('zoom_sheet').addEventListener('click', () => {
-    renderer.sheetScale();
-    session.sendViewCommand('sheet');
-  });
+  element('zoom_fit').addEventListener('click', () => renderer.fit());
+  element('zoom_sheet').addEventListener('click', () => renderer.sheetScale());
   // "Expand" makes the sheet itself fill the window at the present zoom,
   // in both directions; nothing on it moves (Andy, 2026-10-08 for the
   // width, both ways 2026-10-11).
@@ -1541,21 +1519,9 @@ async function enterSession(invitationText, name, notebook) {
   element('desk').addEventListener('scroll', viewChanged, { passive: true });
   window.addEventListener('pagehide', saveView);
 
-  // The host drives: the host starts new pages, and may let a guest do so.
-  function showHostTools() {
-    // New and Image are the host's; Notebooks, in the same group so that
-    // nothing moves for the host, is everyone's (the chooser reserves
-    // loading).
-    for (const id of ['new_page', 'load_image']) element(id).hidden = !session.mayMakePages();
-    // The Hide tool is for the host and co-hosts; losing the right
-    // while it is chosen puts the pen back in hand.
-    const hideTool = /** @type {HTMLElement} */ (document.querySelector('[data-tool=hide]'));
-    hideTool.hidden = !session.mayMakePages();
-    if (hideTool.hidden && tool === 'hide') /** @type {HTMLElement} */ (document.querySelector('[data-tool=pen]')).click();
-    element('zoom_expand').hidden = !session.mayMakePages();
-    element('zoom_shrink').hidden = !session.mayMakePages();
-  }
-  showHostTools();
+  // Everyone has every button (Andy and his teacher, 2026-10-18; until
+  // then New, Image, Hide, Expand and Shrink were the host's and the
+  // co-hosts').
   element('new_page').addEventListener('click', () => {
     log('New page asked for');
     session.newPage();
@@ -1567,7 +1533,7 @@ async function enterSession(invitationText, name, notebook) {
    * @param {Blob} file
    */
   async function loadImage(file) {
-    if (!session.mayMakePages() || session.page.number === 0) return;
+    if (session.page.number === 0) return;
     try {
       if (!session.addImage(await prepareImage(file))) {
         throw new Error('The page has no room for another image.');
@@ -1588,7 +1554,7 @@ async function enterSession(invitationText, name, notebook) {
     // A deleted notebook leaves the toolbar's list.
     showNotebooks(sessionPicker).catch(() => {});
   });
-  element('load_notebook_page').addEventListener('click', () => { chooser.open(writer.notebook, session.mayMakePages()); });
+  element('load_notebook_page').addEventListener('click', () => { chooser.open(writer.notebook); });
 
   // Image files are chosen, and pictures of the page exported, through a
   // chooser of our own, which begins where the notebooks are.
@@ -2056,20 +2022,6 @@ function showParticipants(session, renderer) {
     const present = participant.self || participant.peer !== null;
     item.classList.toggle('absent', !present);
 
-    if (session.isHost && !participant.self) {
-      // A checkbox with its label to the left, like Extend (Andy, 2026-10-09).
-      const allowLine = document.createElement('label');
-      allowLine.className = 'allow_line';
-      allowLine.setAttribute('data-help', 'Make this participant a co-host: they may then start pages, put images on the page and arrange them, load notebook pages, expand, shrink and hide, as you can.');
-      const allow = document.createElement('input');
-      allow.type = 'checkbox';
-      allow.className = 'allow';
-      allow.checked = session.permitted.has(participant.id);
-      allow.addEventListener('change', () => session.setPermitted(participant.id, allow.checked));
-      allowLine.append('Co-host ', allow);
-      item.append(allowLine);
-    }
-
     const label = document.createElement('label');
     const visible = document.createElement('input');
     visible.type = 'checkbox';
@@ -2082,8 +2034,6 @@ function showParticipants(session, renderer) {
 
     const roles = [];
     if (participant.self) roles.push('you');
-    if (participant.host) roles.push('host');
-    else if (!session.isHost && session.permitted.has(participant.id)) roles.push('co-host');
     if (!present) roles.push('away');
     if (roles.length) {
       const role = document.createElement('span');
diff --git a/client/js/page_file.js b/client/js/page_file.js
index c792c15..82352d0 100644
--- a/client/js/page_file.js
+++ b/client/js/page_file.js
@@ -165,7 +165,7 @@ function strokeShapes(stroke) {
  * @param {object} options
  * @param {string} options.session  The session the page belongs to (its
  *     room id), so that returning to the session continues the page.
- * @param {string} options.hostId
+ * @param {string} options.hostId  Who started the session (`data-host`).
  * @param {Set<string>} [options.hidden]  Layers to leave out: for a picture
  *     of the page as someone shows it, never for the page file itself.
  * @returns {string}  The page file.
diff --git a/client/js/page_model.js b/client/js/page_model.js
index dbcaf4a..88922cd 100644
--- a/client/js/page_model.js
+++ b/client/js/page_model.js
@@ -338,8 +338,8 @@ function withoutData(image) {
 }
 
 /**
- * What identifies a page and gives its size.  The host sends it to the
- * others when the page changes.
+ * What identifies a page and gives its size.  Whoever starts or changes
+ * a page sends it to the others.
  * @typedef {object} PageDescriptor
  * @property {string} id
  * @property {number} number  Counts the pages of a session from 1.
@@ -504,8 +504,8 @@ export class Page {
   /**
    * @param {number} [width]
    * @param {number} [height]
-   * @param {string} [id]      Empty for the placeholder a guest shows
-   *                           before the host's page arrives.
+   * @param {string} [id]      Empty for the placeholder someone joining
+   *                           shows before a page arrives.
    * @param {number} [number]  0 for the placeholder.
    */
   constructor(width = BLANK_PAGE_WIDTH, height = BLANK_PAGE_HEIGHT, id = '', number = 0) {
@@ -781,9 +781,10 @@ export class Page {
   }
 
   /**
-   * Layer ids from bottom to top.  The host's layer is on top so that
-   * corrections lie over the writing they correct.
-   * @param {string} hostId
+   * Layer ids from bottom to top.  The layer of whoever started the
+   * session is on top, so that a teacher's corrections lie over the
+   * writing they correct (a drawing order, not a right).
+   * @param {string} hostId  Who started the session.
    * @returns {string[]}
    */
   layerOrder(hostId) {
diff --git a/client/js/session.js b/client/js/session.js
index ec28d58..d7c4853 100644
--- a/client/js/session.js
+++ b/client/js/session.js
@@ -46,7 +46,6 @@ import { trimTrailingBlankLines } from './text_layout.js';
  * @property {string} name
  * @property {number | null} peer  Relay peer number; null when not connected.
  * @property {boolean} self
- * @property {boolean} host
  */
 
 /**
@@ -64,11 +63,6 @@ import { trimTrailingBlankLines } from './text_layout.js';
  * @property {(byImages: boolean) => void} onPageResized
  *     The page grew (or shrank) around its contents; `byImages` if an
  *     image was added or taken back, not if writing reached an edge.
- * @property {() => void} onPermissionsChanged
- *     Who may start pages changed.
- * @property {(command: 'fit' | 'sheet') => void} onViewCommand
- *     The host pressed "Fit" or "Normal scale": everyone's view follows (Andy,
- *     2026-10-08), each in their own window.
  * @property {() => void} onParticipantsChanged
  * @property {(status: 'connecting' | 'connected' | 'failed', detail?: string) => void} onStatus
  * @property {() => void} [onUndoChanged]
@@ -81,7 +75,9 @@ import { trimTrailingBlankLines } from './text_layout.js';
  * @property {string} roomId
  * @property {CryptoKey} key
  * @property {Identity} identity
- * @property {string} hostId
+ * @property {string} hostId  Who started the session, the id in the
+ *     invitation: the page file records it and that layer is drawn on
+ *     top; it gives no right (everyone has the same, Andy, 2026-10-18).
  * @property {string} name     Our display name.
  * @property {Page} [page]     The page as last saved, when returning to
  *     the session.
@@ -146,13 +142,11 @@ export class Session {
     this.hideEditing = null;
     this.events = events;
 
-    this.isHost = this.identity.id === this.hostId;
-    /** @type {Set<string>}  Guests the host allows to start pages. */
-    this.permitted = new Set();
-    // The host begins a session with page 1.  A guest shows a placeholder
-    // until the host's page arrives.
+    // Whoever starts a session begins on page 1.  Someone joining shows
+    // a placeholder until a page arrives from the others (or starts one
+    // with New, if nobody is there).
     this.page = options.page ??
-      (this.isHost ? new Page(undefined, undefined, randomId(), 1) : new Page());
+      (this.identity.id === this.hostId ? new Page(undefined, undefined, randomId(), 1) : new Page());
     this.ownLayer = this.page.layer(this.identity.id, this.name);
     this.page.recomputeStrokeBounds();
     this.page.updateExtent();
@@ -161,13 +155,11 @@ export class Session {
     this.participants = new Map();
     this.participants.set(this.identity.id, {
       id: this.identity.id, name: this.name, peer: null, self: true,
-      host: this.identity.id === this.hostId,
     });
     for (const layer of this.page.layers.values()) {
       if (layer.id === this.identity.id) continue;
       this.participants.set(layer.id, {
         id: layer.id, name: layer.name || 'Unnamed', peer: null, self: false,
-        host: layer.id === this.hostId,
       });
     }
 
@@ -241,34 +233,10 @@ export class Session {
     return this.page.layerOrder(this.hostId);
   }
 
-  // Pages.
-
-  /** @returns {boolean}  Whether we may start pages: the host, or a guest the host allows. */
-  mayMakePages() {
-    return this.isHost || this.permitted.has(this.identity.id);
-  }
-
-  /**
-   * The host's "Fit" or "Normal scale" goes to everyone.  Only the host's does.
-   * @param {'fit' | 'sheet'} command
-   */
-  sendViewCommand(command) {
-    if (!this.isHost) return;
-    this.send(0, { type: 'view', command });
-  }
-
-  /**
-   * Allow a guest to start pages, or stop allowing it.  Only the host may.
-   * @param {string} id
-   * @param {boolean} allowed
-   */
-  setPermitted(id, allowed) {
-    if (!this.isHost || id === this.identity.id) return;
-    if (allowed) this.permitted.add(id);
-    else this.permitted.delete(id);
-    this.send(0, { type: 'permissions', ids: [...this.permitted] });
-    this.events.onPermissionsChanged();
-  }
+  // Pages.  Everyone may start, load and change them (Andy and his
+  // teacher, 2026-10-18: the host's rights and the co-host went; what
+  // an accident costs is said in the documentation, and the page left
+  // is kept in every notebook).
 
   /**
    * The page's rectangle may have changed with its contents.
@@ -279,11 +247,10 @@ export class Session {
   }
 
   /**
-   * Start a new blank page for everyone.  The host may; so may a guest the
-   * host allows.
+   * Start a new blank page for everyone.  Someone with no page yet (the
+   * others gone) starts page 1.
    */
   newPage() {
-    if (!this.mayMakePages()) return;
     const page = new Page(undefined, undefined, randomId(), this.page.number + 1);
     page.updateExtent();
     this.replacePage(page);
@@ -292,7 +259,6 @@ export class Session {
 
   /**
    * Add an image to the page for everyone, below the images already on it.
-   * The host may; so may a guest the host allows.
    * @param {object} prepared
    * @param {PageImage['type']} prepared.type
    * @param {Uint8Array<ArrayBuffer>} prepared.data
@@ -303,7 +269,7 @@ export class Session {
    */
   addImage(prepared) {
     const page = this.page;
-    if (!this.mayMakePages() || page.number === 0) return false;
+    if (page.number === 0) return false;
     const place = placeImage(page, prepared.naturalWidth, prepared.naturalHeight);
     if (!page.hasRoomForImage(prepared.data.length, place.y + place.height)) return false;
     /** @type {PageImage} */
@@ -333,7 +299,7 @@ export class Session {
    */
   addHide(rect) {
     const page = this.page;
-    if (!this.mayMakePages() || page.number === 0 || page.hides.length >= MAX_PAGE_HIDES) return false;
+    if (page.number === 0 || page.hides.length >= MAX_PAGE_HIDES) return false;
     const hide = {
       id: randomId(), x: Math.round(rect.left), y: Math.round(rect.top),
       width: Math.round(rect.width), height: Math.round(rect.height),
@@ -377,7 +343,7 @@ export class Session {
   placeHideByHand(index, rect) {
     const page = this.page;
     const hide = page.hides[index];
-    if (!this.mayMakePages() || !hide) return;
+    if (!hide) return;
     hide.x = Math.round(rect.left);
     hide.y = Math.round(rect.top);
     hide.width = Math.round(rect.width);
@@ -394,7 +360,7 @@ export class Session {
   removeHide(index) {
     const page = this.page;
     const hide = page.hides[index];
-    if (!this.mayMakePages() || !hide) return false;
+    if (!hide) return false;
     page.hides.splice(index, 1);
     page.imagesRevision += 1;
     this.sendPageNow();
@@ -424,7 +390,7 @@ export class Session {
    */
   raiseImage(index) {
     const page = this.page;
-    if (!this.mayMakePages() || index < 0 || index >= page.images.length) return index;
+    if (index < 0 || index >= page.images.length) return index;
     if (index !== page.images.length - 1) {
       const [image] = page.images.splice(index, 1);
       page.images.push(image);
@@ -443,7 +409,7 @@ export class Session {
    */
   placeImageByHand(index, rect) {
     const page = this.page;
-    if (!this.mayMakePages() || index < 0 || index >= page.images.length) return index;
+    if (index < 0 || index >= page.images.length) return index;
     index = this.raiseImage(index);
     const image = page.images[index];
     image.x = Math.round(rect.left);
@@ -496,7 +462,7 @@ export class Session {
    */
   expandPage(width, height) {
     const page = this.page;
-    if (!this.mayMakePages() || page.number === 0) return false;
+    if (page.number === 0) return false;
     // Equally on both sides, and top and bottom, of the PAGE as it is,
     // writing included (the sheet may lie inside a page that writing has
     // grown; measured from the sheet, the page came out short, Andy,
@@ -530,7 +496,7 @@ export class Session {
    */
   shrinkPage() {
     const page = this.page;
-    if (!this.mayMakePages() || page.number === 0) return false;
+    if (page.number === 0) return false;
     // The blank lines at the end of one's own text blocks go first (Andy,
     // 2026-10-14); another's blocks are theirs, trimmed when they finish
     // typing.  Each trim is a gesture of its own to undo; a block being
@@ -564,7 +530,7 @@ export class Session {
   removeImage(index) {
     const page = this.page;
     const image = page.images[index];
-    if (!image || !(this.mayMakePages() || image.by === this.identity.id)) return false;
+    if (!image) return false;
     page.images.splice(index, 1);
     page.imagesRevision += 1;
     this.imageTransfers.delete(image.hash);
@@ -581,7 +547,6 @@ export class Session {
    * @param {Page} kept  As read from the page file.
    */
   loadPage(kept) {
-    if (!this.mayMakePages()) return;
     const page = new Page(kept.baseWidth, kept.baseHeight, randomId(), this.page.number + 1);
     page.baseLeft = kept.baseLeft;
     page.baseTop = kept.baseTop;
@@ -595,9 +560,7 @@ export class Session {
       }
       for (const block of layer.texts.values()) copy.texts.set(block.id, { ...block, lines: block.lines.slice() });
       if (!this.participants.has(id)) {
-        this.participants.set(id, {
-          id, name: layer.name || 'Unnamed', peer: null, self: false, host: id === this.hostId,
-        });
+        this.participants.set(id, { id, name: layer.name || 'Unnamed', peer: null, self: false });
       }
     }
     page.recomputeStrokeBounds();
@@ -744,15 +707,18 @@ export class Session {
 
   /**
    * Move to a page that another participant is on, if it is newer than
-   * ours.  Pages are numbered by the host, so the highest number is the
-   * session's current page; between two pages of the same number, the
-   * host's is taken.  If it is the page we are on, it may have gained
+   * ours.  Whoever presses New numbers the page one past their own, so
+   * the highest number is the session's current page; between two
+   * different pages of the same number (two people pressed New at the
+   * same moment, or apart while disconnected) the one with the greater
+   * id is taken, the same choice on every machine, and the loser's page
+   * is kept in its notebook like any page left (2026-10-18; the host's
+   * won until then).  If it is the page we are on, it may have gained
    * images.
    * @param {unknown} received  A page descriptor.
-   * @param {boolean} fromHost
    * @param {number} peer  Who told us.
    */
-  considerPage(received, fromHost, peer) {
+  considerPage(received, peer) {
     const descriptor = cleanPageDescriptor(received);
     if (!descriptor) return;
     if (descriptor.id === this.page.id) {
@@ -760,44 +726,12 @@ export class Session {
       return;
     }
     const newer = descriptor.number > this.page.number ||
-      (descriptor.number === this.page.number && fromHost);
+      (descriptor.number === this.page.number && descriptor.id > this.page.id);
     if (!newer) return;
     this.replacePage(Page.from(descriptor));
     this.pageSourcePeer = peer;
   }
 
-  /**
-   * Whether a page descriptor from a participant without the right to
-   * make pages is one they may still send: our page, the sheet as it is,
-   * and the images ours with only images they added left out (Andy,
-   * 2026-10-08: whoever added an image may remove it, right or no right).
-   * @param {any} received
-   * @param {string} id  The sender.
-   * @returns {boolean}
-   */
-  removesOnlyOwnImages(received, id) {
-    const descriptor = cleanPageDescriptor(received);
-    const page = this.page;
-    if (!descriptor || descriptor.id !== page.id || descriptor.left !== page.baseLeft ||
-        descriptor.top !== page.baseTop || descriptor.width !== page.baseWidth ||
-        descriptor.height !== page.baseHeight ||
-        JSON.stringify(descriptor.hides) !== JSON.stringify(page.hides)) return false;
-    /** @param {Omit<PageImage, 'data'>} image */
-    const key = (image) => `${image.hash} ${image.x} ${image.y} ${image.width} ${image.height} ${image.by}`;
-    let at = 0;
-    let removed = 0;
-    for (const ours of page.images) {
-      if (at < descriptor.images.length && key(descriptor.images[at]) === key(ours)) {
-        at += 1;
-      } else if (ours.by === id) {
-        removed += 1;
-      } else {
-        return false;
-      }
-    }
-    return at === descriptor.images.length && removed > 0;
-  }
-
   /**
    * Another participant's list of the images on the page we are on.  The
    * list with the higher revision is the later one.  Of two different
@@ -1116,7 +1050,6 @@ export class Session {
         return 'a move of a shape';
       case 'hide': {
         const page = this.page;
-        if (!this.mayMakePages()) return null;
         const index = page.hides.findIndex((one) => one.id === entry.id);
         if (entry.before === null) {
           if (index < 0) return null;
@@ -1197,7 +1130,6 @@ export class Session {
       type: 'hello', reply, name: this.name, publicKey: this.identity.publicKey,
       signature: await signClaim(this.identity, this.roomId, peer),
       page: this.page.number > 0 ? this.page.descriptor() : null,
-      permitted: this.isHost ? [...this.permitted] : undefined,
     }));
   }
 
@@ -1305,9 +1237,8 @@ export class Session {
     const previous = this.participants.get(id);
     if (previous && previous.peer !== null) this.peerIds.delete(previous.peer);
     this.peerIds.set(peer, id);
-    this.participants.set(id, { id, name, peer, self: false, host: id === this.hostId });
-    if (id === this.hostId) this.receivedPermissions(message.permitted);
-    this.considerPage(message.page, id === this.hostId, peer);
+    this.participants.set(id, { id, name, peer, self: false });
+    this.considerPage(message.page, peer);
     // This peer is on our page: it can give us the images we lack.
     if (message.page?.id === this.page.id) this.requestImages(peer);
     this.page.layer(id, name);
@@ -1329,20 +1260,12 @@ export class Session {
     const id = this.peerIds.get(peer);
     if (!id) return;
     if (message.type === 'page') {
-      if (id === this.hostId || this.permitted.has(id)) this.considerPage(message.page, true, peer);
-      else if (this.removesOnlyOwnImages(message.page, id)) this.considerPage(message.page, false, peer);
-      return;
-    }
-    if (message.type === 'permissions') {
-      if (id === this.hostId) this.receivedPermissions(message.ids);
-      return;
-    }
-    if (message.type === 'view') {
-      if (id === this.hostId && (message.command === 'fit' || message.command === 'sheet')) {
-        this.events.onViewCommand(message.command);
-      }
+      this.considerPage(message.page, peer);
       return;
     }
+    // 'permissions' and 'view' came from a host, until 2026-10-18; an
+    // older client's are ignored.
+    if (message.type === 'permissions' || message.type === 'view') return;
     if (message.type === 'image') {
       this.receivedImagePiece(message);
       return;
@@ -1482,19 +1405,6 @@ export class Session {
     }
   }
 
-  /**
-   * The host said who may start pages.
-   * @param {unknown} ids
-   */
-  receivedPermissions(ids) {
-    if (!Array.isArray(ids)) return;
-    const permitted = new Set(ids.filter(validId));
-    const same = permitted.size === this.permitted.size && [...permitted].every((id) => this.permitted.has(id));
-    if (same) return;
-    this.permitted = permitted;
-    this.events.onPermissionsChanged();
-  }
-
   /**
    * Whether to accept a snapshot of a layer from a peer.  A participant may
    * always send their own layer.  The peer that moved us to this page may
@@ -1543,7 +1453,6 @@ export class Session {
       if (!this.participants.has(layerId)) {
         this.participants.set(layerId, {
           id: layerId, name: snapshot.name || 'Unnamed', peer: null, self: false,
-          host: layerId === this.hostId,
         });
         this.events.onParticipantsChanged();
       }
diff --git a/client/kokkoja.css b/client/kokkoja.css
index 1d93ce2..8697093 100644
--- a/client/kokkoja.css
+++ b/client/kokkoja.css
@@ -529,8 +529,6 @@ h2 {
 .session_body li.absent { color: var(--muted); }
 .session_body li label { flex: 1; }
 .session_body li .role { font-size: 0.8rem; color: var(--muted); }
-.session_body li .allow_line { order: 1; display: flex; align-items: center; gap: 0.3rem; font-size: 0.8rem; color: var(--muted); cursor: pointer; }
-.session_body li .allow_line input { margin: 0; }
 .invitation_line { display: flex; gap: 0.5rem; align-items: center; }
 .invitation_line input { flex: 1; min-width: 0; }
 /* The invitation as a QR code, for the camera of a phone or a tablet. */
diff --git a/tests/test_end_to_end.py b/tests/test_end_to_end.py
index d959d10..42909e7 100644
--- a/tests/test_end_to_end.py
+++ b/tests/test_end_to_end.py
@@ -136,7 +136,7 @@ PAGE_STATE = """
         hash: one.hash, x: one.x, y: one.y, width: one.width, height: one.height,
         ready: one.data !== null, shown: i < shown.length && !shown[i].hidden})),
       participants: session.participantList().map(
-        (p) => ({name: p.name, host: p.host, present: p.self || p.peer !== null})),
+        (p) => ({name: p.name, present: p.self || p.peer !== null})),
       layers,
       texts,
     };
@@ -265,14 +265,6 @@ PEN_WAVE = """
     page.setPointerCapture = capture;
 """
 
-# Clicks the host's "Co-host" box beside the named participant.
-TOGGLE_PERMISSION = """
-    const find = () => [...document.querySelectorAll('#participants li')]
-      .find((li) => li.textContent.includes(arguments[0])).querySelector('.allow');
-    find().click();
-    return String(find().checked);    // The list is rebuilt by the click.
-"""
-
 # Makes an image of the given size in pixels and puts it on the page, as
 # the "Image" button does with a file.  Arguments: width, height, kind
 # ('png' or 'jpeg'), a resolution in dots per inch to record in the file,
@@ -799,7 +791,10 @@ class EndToEndTest(unittest.TestCase):
 
     def test_browser_guest(self):
         """A guest with nothing installed: the host's invitation is a link to
-        the Kokkoja web site, and the guest's notebook is in the browser."""
+        the Kokkoja web site, and the guest's notebook is in the browser.
+        Everyone has every button (2026-10-18): the guest puts an image on
+        the page, goes on without the host, and a newcomer to an empty
+        room starts page 1."""
         firefox = self.firefox
         today = time.strftime("%Y_%m_%d")
 
@@ -959,14 +954,11 @@ class EndToEndTest(unittest.TestCase):
         self.assertTrue(picture.startswith(b"\x89PNG"))
         self.assertIn("downloads", firefox.run("return document.getElementById('notice').textContent;"))
 
-        # Allowed by the host, the guest puts an image on the page (the
-        # file would come from the browser's own chooser).
-        self.assertTrue(firefox.run("return document.getElementById('new_page').hidden;"))
-        firefox.switch_to(host_tab)
-        self.assertEqual(firefox.run(TOGGLE_PERMISSION, "Guest"), "true")
-        firefox.switch_to(guest_tab)
-        self.wait_until(lambda s: not firefox.run("return document.getElementById('new_page').hidden;"),
-                        "the guest to be allowed to start pages")
+        # The guest puts an image on the page (the file would come from the
+        # browser's own chooser); nobody's leave is needed (2026-10-18).
+        self.assertFalse(firefox.run("return document.getElementById('new_page').hidden;"))
+        self.assertFalse(firefox.run("return document.getElementById('load_image').hidden;"))
+        self.assertIsNone(firefox.run("return document.querySelector('#participants .allow');"), "no Co-host box")
         firefox.run_until_done(LOAD_IMAGE, 300, 400, "png", 0, False)
         guest = self.wait_until(lambda s: s["image"] and s["image"]["ready"], "the guest's image")
         firefox.switch_to(host_tab)
@@ -985,9 +977,34 @@ class EndToEndTest(unittest.TestCase):
         self.assertEqual(reloaded["layers"]["Guest"], guest["layers"]["Guest"])
         self.assertEqual(len(reloaded["participants"]), 2)
 
-        # The host leaves the session; the tabs are closed for the next test.
+        # The host leaves; the guest goes on, and starts a new page without
+        # anyone's leave.  A newcomer to the room with nobody left in it
+        # has no page, and New gives page 1; between two different pages
+        # of one number the greater id wins, on every machine alike.
+        firefox.switch_to(host_tab)
+        firefox.go("about:blank")
+        firefox.switch_to(guest_tab)
+        self.wait_until(lambda s: [p["present"] for p in s["participants"]] == [True, False], "the host to be away")
+        firefox.run("document.getElementById('new_page').click();")
+        self.wait_until(lambda s: s["page"]["number"] == 2, "the guest's new page")
         firefox.in_session("DELETE", "/window")
         firefox.switch_to(host_tab)
+        firefox.go(self.address("Late", join=urllib.parse.unquote(link.split("#join=")[1])))
+        self.enter_name("Latecomer", "join_session")
+        self.wait_until(lambda s: s["status"] == "Connected", "the latecomer to connect")
+        time.sleep(0.5)
+        self.assertEqual(self.state()["page"]["number"], 0)
+        self.assertIn("New starts one", firefox.run("return document.getElementById('notice').textContent;"))
+        firefox.run("document.getElementById('new_page').click();")
+        self.wait_until(lambda s: s["page"]["number"] == 1, "the latecomer's page 1")
+        tie = lambda id: firefox.run("""
+            const session = window.kokkoja.session;
+            session.considerPage({...session.page.descriptor(), id: arguments[0]}, 0);
+            return [session.page.number, session.page.id];
+        """, id)
+        own = firefox.run("return window.kokkoja.session.page.id;")
+        self.assertEqual(tie("-" * 22), [1, own], "a lesser id loses")
+        self.assertEqual(tie("z" * 22), [1, "z" * 22], "a greater id wins")
         firefox.go("about:blank")
 
     def test_tooltips(self):
@@ -1086,7 +1103,8 @@ class EndToEndTest(unittest.TestCase):
 
     def test_hide_rectangles(self):
         """The teacher's requests of 2026-10-08: a Hide rectangle covers part
-        of the page in white for everyone, marked by blue corners."""
+        of the page in white for everyone, marked by blue corners.  Everyone
+        has the tool and may move or remove a Hide (2026-10-18)."""
         firefox = self.firefox
         host_tab = firefox.current_tab()
         firefox.go(self.address("Late"))
@@ -1096,7 +1114,7 @@ class EndToEndTest(unittest.TestCase):
         firefox.go(self.address("Student", join=invitation))
         self.enter_name("Watcher", "join_session")
         self.wait_until(lambda s: s["page"]["number"] == 1 and len(s["participants"]) == 2, "the watcher")
-        self.assertTrue(firefox.run("return document.querySelector('[data-tool=hide]').hidden;"))
+        self.assertFalse(firefox.run("return document.querySelector('[data-tool=hide]').hidden;"))
         firefox.switch_to(host_tab)
         self.assertFalse(firefox.run("return document.querySelector('[data-tool=hide]').hidden;"))
 
@@ -1121,8 +1139,9 @@ class EndToEndTest(unittest.TestCase):
         self.assertFalse(white_at(hide[0] + hide[2] + 100, hide[1] + hide[3] + 100))
 
         # The watcher sees it; hiding the host's layer on the watcher's
-        # screen does not uncover it; the watcher can neither move nor
-        # remove it.
+        # screen does not uncover it.  The watcher moves it by a hold, as
+        # anyone may (2026-10-18), and takes the move back with Undo; the
+        # host sees both.
         firefox.switch_to(guest_tab)
         self.wait_until(lambda s: s["hides"] == made["hides"], "the Hide to reach the watcher")
         firefox.run("""
@@ -1134,9 +1153,16 @@ class EndToEndTest(unittest.TestCase):
         origin = self.state()["origin"]
         firefox.run_until_done(PEN_HOLD, (hide[0] + 50 - origin[0]) * vscale, (hide[1] + 50 - origin[1]) * vscale,
                                100 * vscale, 0, 800)
-        firefox.run(ERASER_AT, hide[0] + 50, hide[1] + 50, 5)
-        time.sleep(0.5)
-        self.assertEqual(self.state()["hides"], made["hides"])
+        moved_by_watcher = [hide[0] + 100, *hide[1:]]
+        self.wait_until(lambda s: s["hides"] == [moved_by_watcher], "the Hide moved by the watcher")
+        firefox.switch_to(host_tab)
+        self.wait_until(lambda s: s["hides"] == [moved_by_watcher], "the watcher's move to reach the host")
+        firefox.switch_to(guest_tab)
+        firefox.run("document.getElementById('undo').click();")
+        self.wait_until(lambda s: s["hides"] == made["hides"], "the watcher's Undo")
+        firefox.switch_to(host_tab)
+        self.wait_until(lambda s: s["hides"] == made["hides"], "the Undo to reach the host")
+        firefox.switch_to(guest_tab)
 
         # The host moves it by a hold, resizes it freely from a corner,
         # and the file carries it above every layer.
@@ -1409,43 +1435,36 @@ class EndToEndTest(unittest.TestCase):
         firefox.run("document.querySelector('[data-tool=pen]').click();")
         scaled = erased_not
 
-        # A guest given the right adds an image, keeps the power to remove it
-        # after the right is withdrawn, and cannot remove the host's.
-        self.assertEqual(firefox.run(TOGGLE_PERMISSION, "Viewer"), "true")
+        # The guest adds an image and removes it with a tap of the eraser,
+        # nobody's leave being needed (2026-10-18).
         firefox.switch_to(guest_tab)
-        self.wait_until(lambda s: not firefox.run("return document.getElementById('new_page').hidden;"),
-                        "the viewer to be allowed")
+        self.assertFalse(firefox.run("return document.getElementById('new_page').hidden;"))
         firefox.run_until_done(LOAD_IMAGE, 200, 100, "png", 0, False)
         added = self.wait_until(lambda s: len(s["images"]) == 3, "the viewer's image")
         firefox.switch_to(host_tab)
         self.wait_until(lambda s: len(s["images"]) == 3, "the viewer's image to reach the host")
-        self.assertEqual(firefox.run(TOGGLE_PERMISSION, "Viewer"), "false")
         firefox.switch_to(guest_tab)
-        self.wait_until(lambda s: firefox.run("return document.getElementById('new_page').hidden;"),
-                        "the right to be withdrawn")
         own = added["images"][2]
         firefox.run(ERASER_AT, own["x"] + 100, own["y"] + 50, 5)
         self.wait_until(lambda s: len(s["images"]) == 2, "the viewer's own image removed")
-        hosts = self.state()["images"][1]
-        firefox.run(ERASER_AT, hosts["x"] + 50, hosts["y"] + 50, 5)
-        time.sleep(0.5)
-        self.assertEqual(len(self.state()["images"]), 2)
         firefox.switch_to(host_tab)
         self.wait_until(lambda s: len(s["images"]) == 2, "the removal to reach the host")
         firefox.switch_to(guest_tab)
 
-        # The viewer sees the same, and cannot move an image: a hold there
-        # draws a dot instead.
-        firefox.switch_to(guest_tab)
+        # The viewer sees the same, and moves the host's image by a hold,
+        # which draws no dot; the host sees the move.
         viewer = self.wait_until(lambda s: s["images"] and rect(s, 1) == rect(scaled, 1), "the viewer's copy")
         self.assertEqual(viewer["images"][1]["hash"], scaled["images"][1]["hash"])
         vscale = firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;")
+        viewer_strokes = len(viewer["layers"].get("Viewer", []))
         firefox.run_until_done(PEN_HOLD, (viewer["images"][1]["x"] + 50 - viewer["origin"][0]) * vscale,
                                (viewer["images"][1]["y"] + 50 - viewer["origin"][1]) * vscale, 60 * vscale, 0, 800)
-        time.sleep(0.5)
-        after = self.state()
-        self.assertEqual(rect(after, 1), rect(scaled, 1))
-        self.assertEqual(len(after["layers"].get("Viewer", [])), 1)
+        after = self.wait_until(lambda s: s["images"][1]["x"] == scaled["images"][1]["x"] + 60, "the image moved by the viewer")
+        self.assertEqual(rect(after, 1)[1:], rect(scaled, 1)[1:])
+        self.assertEqual(len(after["layers"].get("Viewer", [])), viewer_strokes)
+        firefox.switch_to(host_tab)
+        self.wait_until(lambda s: s["images"][1]["x"] == scaled["images"][1]["x"] + 60, "the viewer's move to reach the host")
+        firefox.switch_to(guest_tab)
 
         firefox.in_session("DELETE", "/window")
         firefox.switch_to(host_tab)
@@ -1501,8 +1520,9 @@ class EndToEndTest(unittest.TestCase):
         image (and, until 2026-10-14, every Hide and own text rectangle,
         which carry blue corners at all times since), a drag inside one
         moves it and a drag on a corner resizes it, at once, no hold; a
-        press elsewhere does nothing.  A guest without the right sees no
-        cues, their own text rectangle's corners being drawn anyway."""
+        press elsewhere does nothing.  A guest sees the same cues on the
+        image and the Hide (2026-10-18; none before), and one on their
+        own text."""
         firefox = self.firefox
         host_tab = firefox.current_tab()
         firefox.go(self.address("Late"))
@@ -1640,17 +1660,17 @@ class EndToEndTest(unittest.TestCase):
         firefox.pointer_actions([{"type": "pointerUp", "button": 0}])
         self.assertEqual(cues(), ["image", "hide", "text", "text"])
 
-        # The watcher, without the right, is shown no cue on the image or
-        # the Hide, only on their own text.
+        # The watcher is shown the cues on the image and the Hide too, and
+        # on their own text.
         firefox.switch_to(guest_tab)
         self.wait_until(lambda s: len(s["images"]) == 1 and len(s["hides"]) == 1, "the page at the watcher")
         choose("arrange")
-        self.assertEqual(cues(), [])
+        self.assertEqual(cues(), ["image", "hide"])
         choose("text")
         firefox.run(TEXT_GESTURE, 0.1, 0.8, 0.3, 0.9)
         firefox.type_into(".text_field", "Mine")
         choose("arrange")
-        self.assertEqual(cues(), ["text"])
+        self.assertEqual(cues(), ["image", "hide", "text"])
         mine = self.wait_until(lambda s: s["texts"].get("Watcher") and s["texts"]["Watcher"][0]["text"] == "Mine", "the watcher's box")
         mine = mine["texts"]["Watcher"][0]
         self.assert_hover_cue(mine["x"] + 20, mine["y"] + 20, [mine["x"], mine["y"], mine["width"], mine["height"]], "rect")
@@ -2224,7 +2244,7 @@ class EndToEndTest(unittest.TestCase):
         self.assertNotIn("Copy", names)
         self.assertEqual(len(names), len(set(names)), "no two entries of one name")
         self.assertIn("\nPen\nWrite on the page. Only your own writing can be erased.\n", manual)
-        self.assertIn("\nFit to the window\nShow the whole page in the window.", manual)
+        self.assertIn("\nFit to the window\nShow the whole page in the window, on your screen only.", manual)
         self.assertTrue(all(len(line) <= 80 for line in manual.split("\n")), "wrapped at 80")
         self.assertTrue(any(len(line) > 60 for line in manual.split("\n")), "filled, not one word a line")
         # Every tooltip is in it; those that differ only by a number (the
@@ -2460,7 +2480,6 @@ class EndToEndTest(unittest.TestCase):
                                   "the student to receive the teacher's layer")
         self.assertEqual(student["layers"]["Teacher"], teacher["layers"]["Teacher"])
         teacher_first_page = {"Teacher": teacher["layers"]["Teacher"]}
-        self.assertEqual([p["host"] for p in student["participants"]], [False, True])
 
         # The student writes with a pen; the teacher sees the same strokes.
         for fx in (0.15, 0.4, 0.65):
@@ -2545,12 +2564,11 @@ class EndToEndTest(unittest.TestCase):
         self.assertIn("Already kept", firefox.run(
             "return document.getElementById('notice').textContent;"))
 
-        # Only the host can start a new page.
-        self.assertTrue(firefox.run("return document.getElementById('new_page').hidden;"))
-        firefox.switch_to(teacher_tab)
+        # Everyone has New (2026-10-18; the host alone until then).
         self.assertFalse(firefox.run("return document.getElementById('new_page').hidden;"))
+        firefox.switch_to(teacher_tab)
 
-        # The host starts a new page.  Everyone moves to it, and everyone's
+        # The teacher starts a new page.  Everyone moves to it, and everyone's
         # old page is kept without anyone asking: the teacher's now, the
         # student's already.
         firefox.run("document.getElementById('new_page').click();")
@@ -2624,8 +2642,10 @@ class EndToEndTest(unittest.TestCase):
         self.assertEqual(doubled["strokes"], before["strokes"])
         firefox.run(CTRL_DRAG, 0.5, 0.3, 0.5, 0.3, 104)
         self.assertAlmostEqual(zoom()["width"], before["width"], delta=2)
-        # The host's Fit and Normal scale reach the guest, who then fits the page to
-        # the guest's own window; the guest's own Fit stays the guest's.
+        # Fit and Normal scale are each person's own (2026-10-18; the
+        # host's reached everyone from 2026-10-08 until then): the
+        # teacher's Fit leaves the student's zoom alone, and the student's
+        # Normal scale the teacher's.
         firefox.switch_to(student_tab)
         firefox.run("""
             document.getElementById('desk').dispatchEvent(new WheelEvent('wheel',
@@ -2634,12 +2654,13 @@ class EndToEndTest(unittest.TestCase):
         guest_zoomed = firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;")
         firefox.switch_to(teacher_tab)
         firefox.run("document.getElementById('zoom_fit').click();")
-        firefox.switch_to(student_tab)
-        self.wait_until_true(lambda: firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;"),
-                             lambda v: v < guest_zoomed, "the guest's view to follow the host's Fit")
-        firefox.run("document.getElementById('zoom_sheet').click();")
-        firefox.switch_to(teacher_tab)
         host_scale = firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;")
+        firefox.switch_to(student_tab)
+        time.sleep(0.5)
+        self.assertEqual(firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;"), guest_zoomed)
+        firefox.run("document.getElementById('zoom_sheet').click();")
+        self.assertNotEqual(firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;"), guest_zoomed)
+        firefox.switch_to(teacher_tab)
         time.sleep(0.5)
         self.assertEqual(firefox.run("return window.kokkoja.renderer.cssPixelsPerUnit;"), host_scale)
 
@@ -2679,7 +2700,7 @@ class EndToEndTest(unittest.TestCase):
         self.assertGreater(wide_page["height"], teacher["page"]["height"])
         firefox.switch_to(student_tab)
         self.wait_until(lambda s: s["page"] == wide_page, "the expanded page to reach the student")
-        self.assertTrue(firefox.run("return document.getElementById('zoom_expand').hidden;"))
+        self.assertFalse(firefox.run("return document.getElementById('zoom_expand').hidden;"))
         self.assertEqual(firefox.run("return window.kokkoja.session.page.baseLeft;"),
                          -((wide_page["width"] - teacher["page"]["width"]) // 2))
         # The page file carries the sheet's edges and reads back with them.
@@ -3007,8 +3028,8 @@ class EndToEndTest(unittest.TestCase):
         self.assertEqual(alone["page"], teacher["page"])
         self.assertEqual(alone["image"], teacher["image"])
         self.assertEqual(alone["participants"], [
-            {"name": "Teacher", "host": True, "present": True},
-            {"name": "Student", "host": False, "present": False}])
+            {"name": "Teacher", "present": True},
+            {"name": "Student", "present": False}])
         firefox.run("document.getElementById('zoom_fit').click();")     # The view came back scrolled.
         firefox.drag("#page", 100, 500, 300, 520)
         self.current_page("Teacher notebook", {"Teacher": 1, "Student": 1}, number=3)
@@ -3082,22 +3103,14 @@ class EndToEndTest(unittest.TestCase):
             return [shown.naturalWidth, shown.naturalHeight];
         """), [2400, 1600])
 
-        # The student joins the new session.  The host lets the student
-        # start pages, the student loads an image, and the host withdraws
-        # the permission.
+        # The student joins the new session and starts a page with an
+        # image on it, as anyone may (2026-10-18).
         invitation = firefox.run("return document.getElementById('invitation').value;")
         firefox.switch_to(student_tab)
         firefox.go(self.address("Student", join=invitation))
         self.enter_name("Student", "join_session")
         self.wait_until(lambda s: s["page"]["number"] == 2 and s["image"] and s["image"]["ready"],
                         "the student to reach the large image page")
-        self.assertTrue(firefox.run("return document.getElementById('new_page').hidden;"))
-        firefox.switch_to(teacher_tab)
-        self.assertEqual(firefox.run(TOGGLE_PERMISSION, "Student"), "true")
-        firefox.switch_to(student_tab)
-        self.wait_until(
-            lambda s: not firefox.run("return document.getElementById('new_page').hidden;"),
-            "the student to be allowed to start pages")
         firefox.run_until_done(LOAD_IMAGE, 300, 400, "png", 0, True)
         student = self.wait_until(lambda s: s["page"]["number"] == 3, "the student's image page")
         self.assertEqual(student["page"], {"number": 3, "width": 2970, "height": 2100})
@@ -3106,14 +3119,7 @@ class EndToEndTest(unittest.TestCase):
             lambda s: s["page"]["number"] == 3 and s["image"] and s["image"]["ready"],
             "the student's image to reach the teacher")
         self.assertEqual(teacher["image"], student["image"])
-        self.assertEqual(firefox.run(TOGGLE_PERMISSION, "Student"), "false")
         firefox.switch_to(student_tab)
-        self.wait_until(
-            lambda s: firefox.run("return document.getElementById('new_page').hidden;"),
-            "the student's permission to be withdrawn")
-        firefox.run("window.kokkoja.session.newPage();")
-        time.sleep(1)
-        self.assertEqual(self.state()["page"]["number"], 3)
 
         # Writing past the edge of the page makes the page grow, for
         # everyone, in steps of 5 mm.
@@ -3370,19 +3376,6 @@ class EndToEndTest(unittest.TestCase):
         """), lambda names: "Other notebook" not in names, "the toolbar's list to lose the notebook")
         firefox.run("document.getElementById('chooser_close').click();")
 
-        # A guest has the chooser too, to look at and clear their own
-        # notebook; a card tells them that loading is the host's.
-        firefox.switch_to(student_tab)
-        number = self.state()["page"]["number"]
-        firefox.run("document.getElementById('load_notebook_page').click();")
-        self.wait_until_true(lambda: firefox.run("""
-            return document.querySelectorAll('#chooser_pages .page_card').length;
-        """), lambda n: n >= 1, "the student's chooser to list kept pages")
-        firefox.run("document.querySelector('#chooser_pages .page_card').click();")
-        self.assertIn("Only the host and co-hosts", firefox.run("return document.getElementById('chooser_message').textContent;"))
-        self.assertTrue(firefox.run("return document.getElementById('notebook_chooser').open;"))
-        self.assertEqual(self.state()["page"]["number"], number)
-        firefox.run("document.getElementById('chooser_close').click();")
         firefox.switch_to(teacher_tab)
         # A page that its images have made longer than a sheet is first
         # shown at the scale at which one sheet fits the window.
@@ -3394,7 +3387,20 @@ class EndToEndTest(unittest.TestCase):
             "the loaded page of three images to reach the student")
         self.assertEqual(student["images"], stacked["images"])
         self.assertEqual(firefox.run(VIEW), long_view)
+
+        # The student's chooser loads a kept page for everyone too
+        # (2026-10-18; a card refused until then): a new page, the
+        # teacher following.
+        number = student["page"]["number"]
+        firefox.run("document.getElementById('load_notebook_page').click();")
+        self.wait_until_true(lambda: firefox.run("""
+            return document.querySelectorAll('#chooser_pages .page_card').length;
+        """), lambda n: n >= 1, "the student's chooser to list kept pages")
+        firefox.run("document.querySelector('#chooser_pages .page_card').click();")
+        self.wait_until(lambda s: s["page"]["number"] == number + 1, "the page the student loaded")
+        self.assertFalse(firefox.run("return document.getElementById('notebook_chooser').open;"))
         firefox.switch_to(teacher_tab)
+        self.wait_until(lambda s: s["page"]["number"] == number + 1, "the student's loaded page to reach the teacher")
 
         # Five colours and four widths in the toolbar.  "+" among the
         # colours opens a palette of our own, in which the colours already
@@ -3557,9 +3563,10 @@ class EndToEndTest(unittest.TestCase):
         self.assertTrue(all(abs(a - b) <= 3 for a, b in zip(colours["image"], (200, 60, 60))), colours)
         firefox.run("document.querySelector('#participants input[type=checkbox]').click();")
 
-        # A tap of the eraser on an image removes it, for whoever may make
-        # pages or added the image; a sweep across it does not.  Writing on
-        # it stays; the sheet keeps its size.
+        # A tap of the eraser on an image removes it, by anyone (2026-10-18;
+        # the host, a co-host or whoever added it until then); a sweep
+        # across it does not.  Writing on it stays; the sheet keeps its
+        # size.
         firefox.run("document.getElementById('new_page').click();")
         number = self.wait_until(lambda s: not s["images"], "another new page")["page"]["number"]
         firefox.run_until_done(LOAD_IMAGE, 300, 400, "png", 0, False)
@@ -3571,18 +3578,19 @@ class EndToEndTest(unittest.TestCase):
         firefox.switch_to(student_tab)
         self.wait_until(lambda s: len(s["images"]) == 2 and all(i["ready"] for i in s["images"]),
                         "the two images to reach the student")
-        # Not the student, who has no right and did not add it.
-        firefox.run(ERASER_AT, 1050, 1500, 5)
+        # Not by moving the eraser across it: the student's sweep leaves it.
+        firefox.run(ERASER_AT, 1050, 1500, 100)
         firefox.run(PEN_WAVE, 0.3, 0.5)
         firefox.switch_to(teacher_tab)
         self.wait_until(lambda s: len(s["layers"].get("Student", [])) == 1 and s["layers"]["Student"][0]["done"],
                         "the student's writing on the image")
-        # Not by moving the eraser across it.
-        firefox.run(ERASER_AT, 1050, 1500, 100)
-        time.sleep(0.3)
         self.assertEqual(rectangles(self.state()), rectangles(two))
-        # A tap by the teacher removes it, written on or not.
+        # A tap by the student, who did not add it, removes it, written on
+        # or not; the teacher sees it go.
+        firefox.switch_to(student_tab)
         firefox.run(ERASER_AT, 1050, 1500, 5)
+        self.wait_until(lambda s: len(s["images"]) == 1, "the image removed by the student")
+        firefox.switch_to(teacher_tab)
         one = self.wait_until(lambda s: len(s["images"]) == 1, "the image to be removed")
         self.assertEqual(one["page"], {"number": number, "width": 2970, "height": 3250})
         self.assertEqual(rectangles(one), [[1335, 50, 300, 400]])