docs(api): per-symbol pages, fuzzy search, deep token linking, hover cards

Rebuild the API Reference around one page per symbol and richer, verified content.

Pages & navigation
- One HTML page per symbol (kw-*, type-*, phase-*, screen-*, fn-*, annot-*, op-*)
  instead of a single scrolling page; namespace overview pages (ns-screen …
  ns-color) and a searchable index (api.html) with client-side fuzzy search.
- Sticky-header scroll offset (scroll-margin) so a jumped-to entry/param/color is
  never hidden, plus a flash highlight on the scrolled-to target.

Deep linking in every snippet & example
- Namespace members split: `Screen`→namespace page, `fill_rectangle`→method page;
  `Color`→palette page, `Charcoal`→its swatch — separately.
- Named arguments (`width:`) link to that parameter's anchor on the method page.
- Hover any token for a summary card built from the real API data (symbols.json).

Content & coverage
- Full authoritative surface documented from the compiler: every keyword, type,
  the 6 phases (Start/Input/FixedUpdate/Update/LateUpdate/Render, each its own
  page), all 22 annotations, namespace methods with parameter docs, builtins,
  the world_* reflection ABI, networking, operators — 155 symbols.
- Longer, clearer explanations; "model"/"model instance" terminology, not "entity";
  descriptive identifiers in every example (Position{column,row}, Velocity{delta_x,
  delta_y}, Health{current,maximum}, Player/Enemy) — no Pos/Seg/x/dx.
- Accuracy fixes from compiler ground-truth: world_count() takes no arg,
  world_query_next(property, cursor) arg order, event fields bind by name; dropped
  `when` and `module` (not in the self-hosted parser).

Tooling
- inventory.json + check.py: coverage guard (every symbol has a page), duplicate-
  token guard, and broken-link guard — fail CI so docs can't drift.
- validate.py: compiles every ```ludic example against bin/ludicc (158 compile).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/language/operators/op-access.md

@@ -3,9 +3,15 @@ id: op-access
 name: Member & index
 category: operators
 kind: operator
-sig: x.field   buf[i]   s[a..b]
-tip: Field/method access, element index, and string slice (a fresh substring).
+sig: x.field   buffer[i]   text[a..b]
+tip: Field access, element index, and string slice — usable as value or target.
 order: 6
 ---
 
-Field/method access, element index, and string slice (a fresh substring).
+The access operators reach into a compound value. `value.field` reads or writes a property field and chains freely (`route.next.column`); `buffer[index]` reads or writes one element of a slice or raw buffer; and `text[start..end]` produces a fresh substring of the bytes in the half-open range, while `text[index]` reads a single byte as an `int` code point. Each form works both as a <b>value</b> and as an <b>assignment target</b>, and they compose — `route[index].column = 0` is one address computation. Field access also binds method-style calls like `Screen.fill_rectangle`.
+
+```ludic
+let head_column: int = segments[0].column
+segments[0].column = head_column + 1
+let extension: str = file_name[len(file_name) - 4 .. len(file_name)]
+```