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/builtins/fn-quit.md

@@ -5,8 +5,22 @@ category: builtins
 kind: builtin
 tokens: quit
 sig: quit()
-tip: Stop the game loop after this frame.
+tip: Stop the game loop cleanly after the current frame finishes.
 order: 2
 ---
 
-Stop the game loop after this frame.
+Signals the runtime to stop the game loop after the current frame completes, ending the program in an orderly way. Because it lets the in-progress frame finish, any drawing you have already queued for this frame is still presented. Use it for a "quit to desktop" action, to end a headless test once its work is done, or to stop on a win/lose condition. For an immediate, mid-frame stop with a status code instead, use <code>exit</code>. It takes no arguments.
+
+```ludic
+program QuitOnKey {
+  handler ReadInput phase Input {
+    if Input.key() == 'q' { quit() }
+  }
+
+  handler DrawWorld phase Render {
+    Screen.clear(Color.MidnightBlue)
+    Screen.draw_text(x: 8, y: 8, text: "PRESS Q TO QUIT", color: Color.White, scale: 1)
+    Screen.show()
+  }
+}
+```