docs(launcher): add Call to Play specification and design reference

Extend the launcher design specification and prototype reference with the
"Call to Play" multiplayer coordination feature and clean up top-bar chrome.

Key additions and changes:
- Spec & Roadmap: Document Call to Play mechanics in SPEC.md, including Play
  Now / Scheduled call flavors, 15-minute check-in windows, top-bar button
  with active count badge, quick-bar ticker stack above grid, overlay modal,
  and per-call group chat. Update design/README.md.
- Components & Logic: Add calltoplay.jsx and ctp-chat.jsx components for call
  creation, status progression, and chat. Extend data.jsx with a mock peer
  roster (PEERS) and helper functions for peer install count tracking.
- Top-bar Cleanup: Move game-folder configuration from top bar into Settings ->
  Library, freeing top-bar space for the Call to Play action button.
- Styling & Layout: Add CTP quick-bar, ticker, badge, card, and chat styles to
  styles.css, and integrate CTP components into launcher.jsx, components.jsx,
  and SoftLAN Launcher.html.

Test Plan:
- `git diff --cached --check` -- passed (no trailing whitespace or conflict markers)
- `cargo check --workspace` -- passed cleanly
- Manual review of staged diff across 9 design/launcher files -- confirmed clean staging

design/README.md

@@ -23,9 +23,11 @@ design_handoff_softlan_launcher/
 │   └── design_reference/    the working prototype the spec describes
 │       ├── SoftLAN Launcher.html   open this to see all screens/variants
 │       ├── styles.css
-│       ├── data.jsx                mock catalog + format helpers
+│       ├── data.jsx                mock catalog + LAN peer roster + format helpers
 │       ├── components.jsx          Icon set, cards, modals, Settings dialog
-│       └── launcher.jsx            composes chrome + grid + modals
+│       ├── ctp-chat.jsx            Call-to-Play chat panel + shared helpers
+│       ├── calltoplay.jsx          Call-to-Play: quick bars, overlay, create form
+│       └── launcher.jsx            composes chrome + grid + modals + Call to Play
 │
 └── logo/                ← THE BRAND MARK
     ├── INTEGRATION.md       how to ship the logo (component + assets + lockup)
@@ -75,8 +77,11 @@ placeholder for it.
 ## Status
 
 - **Launcher:** high-fidelity, decisions locked. Variant **A** is the chosen
-  chrome. Open questions (empty/error states, logs viewer, keyboard grid nav,
-  German strings, "server running" state) are listed at the end of `SPEC.md`.
+  chrome. Includes **Call to Play** (rally the LAN around a game + time — live
+  or scheduled, with RSVP, check-in window, and per-call chat). Open questions
+  (empty/error states, logs viewer, keyboard grid nav, German strings, "server
+  running" state, real-time transport for Call to Play) are listed at the end
+  of `SPEC.md`.
 - **Logo:** final. Live component + static assets + horizontal lockup (dark and
   light) all included.