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.h

@@ -17,23 +17,42 @@ public:
     Argtype()
         : m_name("default")
         , m_desc("default argument type")
-        , m_symbolic_pattern(".+")
-        , m_pattern(".+")
+        , m_symbolic_pattern(R"((?:.|\n)*)")
+        , m_pattern(R"((?:.|\n)*)")
         , m_python_cast("str")
         , m_python_format()
+        , m_regex(std::regex(R"((?:.|\n)*)"))
         , m_loc()
         {};
 
     Argtype(std::string name, std::string desc, std::string symbolic_pattern, std::string pattern,
-            std::string python_cast, modify_string_f python_format,
+            std::string default_value, std::string python_cast, modify_string_f python_format,
             const Locator& loc);
 
     std::string python_value(const std::string& var_name, std::vector<std::string> value, size_t name_size);
 
+    // True for the match-everything pattern shared by the string family
+    // (string, rest, literal, and the default type).  Validating against
+    // it is pointless, and running std::regex over a large value (e.g.
+    // @document's :text holding a whole document) overflows the regex
+    // executor's recursion stack.
+    bool matches_all() const { return m_pattern == R"((?:.|\n)*)"; };
+
     std::string m_name {};
     std::string m_desc {};
     std::string m_symbolic_pattern {};
     std::string m_pattern {};
+    // Default value for parameters of this type; a default given in a
+    // klammer's parameter declaration overrides it (see
+    // parse_optional_parameter).  Useful for single-purpose types
+    // (cell_hpos, column_width); general types (bool, float) have no
+    // sensible universal default and leave it empty.
+    std::string m_default {};
+    // Type parameter for parameterized types like rest(2): the value N
+    // is bound around the python cast as (lambda N: <cast>)(2)(...).
+    // Empty means unparameterized; a type with a default parameter
+    // (rest -> "1") is specialized by writing type(N) in a declaration.
+    std::string m_parameter {};
     std::string m_python_cast {};
     modify_string_f m_python_format {};
     std::regex m_regex {};