Typed arguments, calculated tables, spans, closed-world fonts, top-level fnt/ and env/

Sync with klammertext-dev through b90b0e09:

- Argument types end to end: :python_cast values are applied (Python
  @eval receives real bools/numbers/lists), argument values are
  validated against their argtype patterns with the argtype's
  description as the error message, argtypes can declare :default
  (overridable per declaration), and parameterized type families are
  supported: rest(N) casts a rest argument to an N-dimensional list
  (bar-count = dimension).
- Unified indexed_range syntax (selector with parenthesized subsets,
  composable mnemonic names) for table lines and spans.
- Table klammer: caption fonts fixed in both targets, :column_width /
  :leading / :colsep wired, :colspan and :rowspan render (HTML
  attributes; \multicolumn / \multirow), calculated cell values (:calc)
  with prefix operators, display-precision semantics, :calc_format and
  :decimal period|comma.
- Fonts: closed-world resolution on the Klammertext font store
  (infrastructure in mac/font_store; no Google Fonts links or fetch).
  Default fonts live in the top-level fnt/; additional fonts install
  into KLAMMERTEXT_FONTS directories via kdesc --font (list, samples,
  preview, install — classification by font metadata).  CSS font family
  names are quoted (digit-initial families were silently lost).
- Environment files moved from mac/env/ to the top-level env/; shell
  profiles source env/runtime.env.  Dead per-host variants removed.
- Container: fnt/ ships in the image; curl removed (no network use).

mac/argtype_set.h

@@ -17,8 +17,9 @@ public:
 
     std::string replace_symbols(const std::string& pattern, const Locator& loc);
     void check_for_existing_definition(const std::string& name, const Locator& loc);
-    void add(const std::string& name, const std::string& desc, 
-             const std::string& pattern, const std::string& python_cast, modify_string_f python_format,
+    void add(const std::string& name, const std::string& desc,
+             const std::string& pattern, const std::string& default_value,
+             const std::string& python_cast, modify_string_f python_format,
              const Locator& loc);
     void add(std::vector<Katom>::iterator begin, std::vector<Katom>::iterator end, std::vector<Katom>& katoms);
 
@@ -63,7 +64,7 @@ std::vector<std::tuple<std::string, std::string, std::string, std::string, modif
       pyformat_number },
 
     { "float", "a floating-point number",
-      R"([-+]?\d+(\.\d*)?)", "float",
+      R"([-+]?(\d+(\.\d*)?|\.\d+))", "float",
       pyformat_number },
 
     { "fraction", "a number in the form 'n/d'",
@@ -78,9 +79,11 @@ std::vector<std::tuple<std::string, std::string, std::string, std::string, modif
       R"((?:.|\n)*)", "",
       pyformat_dlist },
 
-    { "rest", "a list of strings delimited by the bar character",
-      R"(.*)", "str",
-      pyformat_string },
+    { "rest", "the remaining arguments as a list nested to N dimensions "
+      "(rest(N)); the delimiter for dimension n is a run of n bar "
+      "characters, so | separates elements and || lists of elements",
+      R"((?:.|\n)*)", R"((lambda s : __import__("kutil").rest_split(s, N)))",
+      nullptr },
 
     { "literal", "literal text passed without interpretation",
       R"((?:.|\n)*)", "str",