comments-ux: figma bubble pins, floating panel, seen/reactions/mentions UI, theme follow (0001 A–E + 0002)

- GAL pin = one closed polygon: round body, squared-off bottom-left corner
  ON the anchor; PIN gains unread (accent ring); tuner knobs; shipped
  defaults r9/ring4/alpha.9. DOM hit/highlight sized+offset from a LIVE
  pin-geometry radius store the tuner feeds.
- Floating comments panel: draggable (shared useDraggablePanel with
  always-onscreen restore; overlay FAB retrofitted), collapsible to header,
  header carries add/show-hide/mark-all; unread badges (rose on mention).
- Reactions (emoji-mart lazy, quick-row) + @-mention autocomplete
  (MentionInput; backend roster with presence/author fallback).
- Theme: ?theme= > storage > OS, no-flash boot, toggles (HomePage + overlay
  View row), boot-seeded pcbjam-dark schematic colors + kicadSetColorTheme /
  kicadSetDarkChrome bridges (canvas + wx chrome live flip), light/dark
  variants across all overlay surfaces.
- e2e: panel/seen/reactions/mentions/theme specs + resize-spec geometry;
  bumps pcbjam-shared (flat-key seen/reactions + listCollaborators) and
  wxwidgets (dark chrome) pointers.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HLwn1toiNKi1MgxGKnZTes

web/standalone/index.html

@@ -7,6 +7,25 @@
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
     <link rel="apple-touch-icon" href="/apple-touch-icon.png" />
     <title>PCBJam - KiCad demo</title>
+    <!-- No-flash theme boot (comments-ux 0002): ?theme= (platform hand-off,
+         persisted) > localStorage > OS preference, applied before first paint.
+         Keep the key + precedence in sync with src/lib/theme.ts. -->
+    <script>
+      (function () {
+        try {
+          var p = new URLSearchParams(location.search).get("theme");
+          var t = p === "light" || p === "dark" ? p : null;
+          if (t) localStorage.setItem("pcbjam-theme", t);
+          else t = localStorage.getItem("pcbjam-theme");
+          if (t !== "light" && t !== "dark") {
+            t = matchMedia("(prefers-color-scheme: dark)").matches ? "dark" : "light";
+          }
+          document.documentElement.classList.toggle("dark", t === "dark");
+        } catch (e) {
+          /* storage/matchMedia unavailable — stay light */
+        }
+      })();
+    </script>
     <meta
       name="description"
       content="Early-access alpha of PCBJam — KiCad running in your browser. Open the example boards or your own KiCad project. No install, nothing uploaded."