## What / Why
This PR finishes the desktop refactor: the Tauri app is now a thin shell that launches the web server as a sidecar and loads the UI from `http://127.0.0.1:<port>`. All real backend logic lives in `packages/web/server/index.js`; desktop Rust keeps only native integrations (menu/dialog/notifications/updater/deep-link + window chrome).
This unblocks:
- consistent behavior across web/desktop/vscode (single backend)
- simpler desktop maintenance (no duplicated Rust backend)
- host switching between Local + remote instances in desktop
- reliable cold-start behavior on slow machines (VSCode + desktop)
## Key changes
- Desktop sidecar runtime
- build pipeline to bundle web dist + `openchamber-server` sidecar (`packages/desktop/scripts/build-sidecar.mjs`)
- robust local port selection (prefer saved/default, fallback to random; persisted in `~/.config/openchamber/settings.json`)
- improved PATH handling so the sidecar can locate `opencode` CLI (incl `~/.opencode/bin`, overrides, common bins)
- disable native right-click context menu in production builds (dev keeps it)
- Desktop instance switcher (Tauri-only)
- header button + modal to add/edit/delete remote hosts, set default, probe status/ping, switch back to Local escape hatch
- auth gate includes host switcher so you can recover when a remote host is broken/auth-required
- host list stored desktop-locally (not tied to the currently selected remote server)
- Notifications
- decision logic moved server-side; desktop notifications emitted via sidecar stdout and shown natively by Tauri
- prevent double-notifications on desktop Local origin (UI ignores SSE notification when native path is active)
- restore macOS notification sound
- Updates
- Tauri updater used only when viewing Local instance in desktop shell (avoid “remote web update” triggering desktop restart)
- Settings persistence & UX polish
- persist model favorites/recents via `/api/config/settings` (works for web + desktop; not origin-dependent)
- persist per-project sidebar collapse state in `projects[].sidebarCollapsed` via `/api/config/settings` (with debounce on toggles)
- macOS header sizing/traffic-lights offsets fixed (marketing macOS major injected from desktop; MultiRun header aligned)
- VSCode cold-start: keep retrying provider/agent loads after connection to avoid empty UI on slow machines
- misc lint/type fixes + bun.lock sync
- Desktop bootstrap / resiliency
- show onboarding screen when OpenCode CLI is missing (desktop Local origin), with retry hook to restart OpenCode after install
## Testing notes
- Desktop (macOS): switch Local <-> remote, set default host, verify auth gate recovery, native notifications (with sound), updater gated to Local
- Web: favorites/recents + per-project collapsed state persist across reload/restart
- VSCode: slow startup no longer results in missing providers/agents/models
- Add per-directory tabbed terminal UI with separate buffers
- Persist and restore active tab per directory across sessions
- Fallback to in-memory storage when sessionStorage is unavailable
Add a centralized useEffectiveDirectory hook to resolve the active directory
Use the hook across DiffView, FilesView, GitView, and TerminalView
Fix list styling by rendering ul/ol bullets outside
Introduce a hook to detect text truncation for dynamic UI updates
Replace static marquee spans with a reusable marquee component in files and labels
Enable copying of terminal selection on mouse up and touch end
* feat(terminal): replace xterm with ghostty-web
Replace xterm.js terminal with ghostty-web implementation
Add terminal serialization support for state restoration
Apply custom patches to ghostty-web for enhancements
* feat(terminal): add bun-pty backend support
Switch terminal to ghostty-web with bun-pty backend for better performance
Auto-detect and prefer Bun runtime when available for terminal sessions
Update terminal viewport write queue handling for improved reliability
* fix(terminal): prevent unnecessary resize events
Only report terminal resize when dimensions actually change
Simplify chunk processing state tracking
Disable terminal transparency for consistent rendering
* feat(terminal): increase scrollback and buffer limits
Increase terminal scrollback buffer from 10k to 50k lines
Increase terminal buffer limit from 256k to 1M bytes
Add rate limiting and improve output handling for terminal streams