feat(terminal): refactor runtime and add mobile workspace (#2280)

Replace the legacy terminal flow with a shared authenticated WebSocket
runtime used across web, desktop, relay, and mobile surfaces.

- introduce the v3 terminal protocol with scoped attachments, snapshots,
  ordered output, bounded replay history, reconnects, and explicit lifecycle
- harden PTY creation, restart, resize, close, force-kill, idle cleanup,
  shell selection, login mode, environment sanitization, and appearance sync
- add runtime-aware terminal APIs with relay authentication and Electron parity
- add a fullscreen mobile terminal workspace with touch scrolling,
  long-press selection, safe-area controls, quick keys, and Ctrl/Alt input
- add terminal selection attachments, preview detection, project actions,
  shell settings, and localized UI
- harden Ghostty rendering, resize recovery, Unicode handling, block
  characters, line height, and stale-row behavior
- remove the obsolete terminal SSE path and update reverse-proxy guidance
- expand terminal runtime, transport, input, selection, and store coverage
- avoid duplicate web builds when preparing mobile assets in root CI builds

package.json

@@ -23,7 +23,7 @@
   "scripts": {
     "dev": "node ./scripts/dev-web-hmr.mjs",
     "oc-dev": "node scripts/oc-dev.mjs",
-    "build": "bun run --filter '*' build",
+    "build": "bun run --sequential --filter '!@openchamber/mobile' build && bun run --cwd packages/mobile build:assets",
     "build:web": "bun run --cwd packages/web build",
     "build:ui": "bun run --cwd packages/ui build",
     "build:electron": "bun run --cwd packages/electron build",