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>

tools/docgen/assets/site.css

@@ -192,3 +192,18 @@
 
   .reveal{opacity:0;transform:translateY(16px);transition:opacity .6s ease, transform .6s ease}
   .reveal.in{opacity:1;transform:none}
+
+  /* hover-card + named-arg token (shared with the reference) */
+  .t-arg{color:var(--amber)}
+  .hovercard{position:fixed;z-index:100;max-width:340px;background:var(--panel2);border:1px solid var(--line2);
+    border-radius:12px;padding:12px 14px;box-shadow:0 20px 50px -18px rgba(0,0,0,.8);pointer-events:none}
+  .hc-top{display:flex;align-items:center;gap:9px;margin-bottom:8px}
+  .hc-name{font-family:"JetBrains Mono",monospace;color:var(--head);font-weight:700;font-size:14px}
+  .hc-sig{display:block;color:var(--c-fn);background:var(--c-bg);border:1px solid var(--line);border-radius:7px;
+    padding:6px 9px;font-size:12px;margin-bottom:8px;white-space:pre-wrap}
+  .hc-tip{color:var(--text);font-size:13.5px;line-height:1.5}
+  .hc-foot{color:var(--muted);font-size:11.5px;margin-top:9px;letter-spacing:.3px}
+  .kind-badge{font-size:11px;font-weight:600;letter-spacing:1px;text-transform:uppercase;padding:3px 7px;
+    border-radius:6px;border:1px solid var(--line2);color:var(--muted);background:var(--panel)}
+  .kind-keyword{color:var(--c-key)}.kind-type{color:var(--c-type)}.kind-phase{color:var(--blue)}
+  .kind-method,.kind-builtin{color:var(--c-fn)}.kind-annotation{color:var(--c-annot)}.kind-namespace{color:var(--amber)}