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/screen/screen-fill_rectangle.md

@@ -5,12 +5,43 @@ category: screen
 kind: namespace-method
 tokens: Screen.fill_rectangle
 sig: Screen.fill_rectangle(x, y, width, height, color)
-tip: Draw a filled rectangle.
+tip: Draw a solid, filled rectangle at a pixel position.
 order: 1
+ns: Screen
+member: fill_rectangle
 ---
 
-Draw a filled rectangle.
+Draws a solid block of color from the top-left corner <code>(x, y)</code> spanning <code>width</code> by <code>height</code> pixels. This is the workhorse for drawing tiles, sprites-from-primitives, health bars, and background panels, since a Ludic game paints every pixel itself rather than loading image assets. Coordinates are in pixels measured from the top-left of the screen, so multiply a grid <code>column</code>/<code>row</code> by your tile size to place things on a board. Parts of the rectangle that fall outside the framebuffer are simply clipped.
+
+Parameters:
+- `x` — the left edge, in pixels from the left of the screen
+- `y` — the top edge, in pixels from the top of the screen
+- `width` — the rectangle width in pixels
+- `height` — the rectangle height in pixels
+- `color` — the fill color, e.g. a `Color.*` name or a `0xRRGGBB` literal
 
 ```ludic
-Screen.fill_rectangle(x: 8, y: 8, width: 16, height: 16, color: Color.Crimson)
+program FilledTiles {
+  property Position { column: int = 0, row: int = 0 }
+  model Player { Position }
+
+  const TILE_SIZE: int = 16
+
+  handler SpawnPlayer phase Start {
+    spawn Player { Position { column: 4, row: 3 } }
+  }
+
+  handler DrawWorld phase Render {
+    Screen.clear(Color.MidnightBlue)
+    for (Position) in query [Position, {Player}] {
+      Screen.fill_rectangle(
+        x: Position.column * TILE_SIZE,
+        y: Position.row * TILE_SIZE,
+        width: TILE_SIZE,
+        height: TILE_SIZE,
+        color: Color.LimeGreen)
+    }
+    Screen.show()
+  }
+}
 ```