VS Code: decoration-based matching, Ctrl+K bindings, README overhaul (from dev f8451715e657)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

doc/edit/shared/klammertext_ls.py

@@ -283,6 +283,26 @@ class Server:
                                'kind': 1})
         self.reply(msg_id, highlights)
 
+    def on_klammertext_matchInfo(self, msg_id, params):
+        """Custom request: the full matching story for a cursor position —
+        token, matching token, and whether the pair mismatches.  The VS Code
+        extension draws its live match/mismatch decorations from this
+        (documentHighlight is word-gated in VS Code, so a bare @ close would
+        never trigger it; and it cannot carry the mismatch flag)."""
+        uri = params['textDocument']['uri']
+        text = self.docs.get(uri, '')
+        m = KE.match_at(text, pos_to_offset(text, params['position']))
+        if m is None:
+            self.reply(msg_id, None)
+            return
+        self.reply(msg_id, {
+            'token': offsets_to_range(text, *m['token']),
+            'matchToken': (offsets_to_range(text, *m['match_token'])
+                           if m['match_token'] is not None else None),
+            'mismatch': m['mismatch'],
+            'message': m['message'],
+        })
+
     def on_textDocument_definition(self, msg_id, params):
         uri = params['textDocument']['uri']
         text = self.docs.get(uri, '')