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-while.md

@@ -5,8 +5,29 @@ category: control
 kind: keyword
 tokens: while
 sig: while cond { … }
-tip: Loop while the condition holds.
+tip: Loop as long as a condition holds, re-checking it before each pass.
 order: 1
 ---
 
-Loop while the condition holds.
+A <code>while</code> loop re-evaluates its condition before every pass and runs the body as long as it stays true, so it is the tool when the number of iterations is not known up front. As with `if`, the condition needs no parentheses and the braces are required. `break` leaves the loop immediately and `continue` jumps to the next condition check. When you are simply counting over a fixed range, prefer the numeric `for i in a .. b` loop, which is clearer and binds a fresh index for you; reach for `while` when the step or the stopping test is irregular.
+
+```ludic
+program Countdown {
+  var fuse: int = 5
+  var elapsed_frames: int = 0
+
+  handler Tick phase Update {
+    elapsed_frames = elapsed_frames + 1
+    while fuse > 0 and elapsed_frames % 60 == 0 {
+      fuse = fuse - 1
+      elapsed_frames = elapsed_frames + 1
+    }
+  }
+
+  handler DrawWorld phase Render {
+    Screen.clear(Color.MidnightBlue)
+    Screen.draw_number(x: 8, y: 8, value: fuse, color: Color.Crimson, scale: 3)
+    Screen.show()
+  }
+}
+```