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/control/kw-match.md

@@ -1,12 +1,36 @@
 ---
 id: kw-match
-name: match / when
+name: match
 category: control
 kind: keyword
 tokens: match
-sig: match x { when a, b => … }
-tip: Multi-way branch on a value, matching one or more literals per arm.
+sig: match value { 0, 1 => … _ => … }
+tip: Multi-way branch on one value, matching one or more literals per arm.
 order: 4
 ---
 
-Multi-way branch on a value, matching one or more literals per arm.
+A <code>match</code> replaces an `if`/`else` ladder that tests one value against several constants. It evaluates the subject once, then takes the first arm whose pattern matches; an arm lists one or more literal patterns separated by commas and points at a body with `=>`, and a lone `_` arm is the catch-all default. Patterns are compile-time constants — integers, char literals like `'w'`, or `enum` variants such as `Action.Guard` — which makes `match` ideal for dispatching on a key press, a tile code, or a mode. Each arm's body is a single statement or a `{ … }` block; matching lowers to plain branches, so it is as cheap as the `if` chain it replaces.
+
+```ludic
+program Steering {
+  property Velocity { delta_x: int = 0, delta_y: int = 0 }
+  model Player { Velocity }
+
+  handler Boot phase Start {
+    spawn Hero { Velocity { delta_x: 0, delta_y: 0 } }
+  }
+
+  handler ReadKeys phase Input {
+    let pressed = Input.key()
+    for (velocity) in query [Velocity, {Player}] {
+      match pressed {
+        'w' => velocity.delta_y = -1
+        's' => velocity.delta_y = 1
+        'a', 'h' => velocity.delta_x = -1
+        'd', 'l' => velocity.delta_x = 1
+        _ => velocity.delta_x = 0
+      }
+    }
+  }
+}
+```