opentui(phase3): launcher integration — HERMES_TUI_ENGINE dual-engine

hermes --tui launches the native OpenTUI engine (Bun) when
HERMES_TUI_ENGINE=opentui (env) or display.tui_engine=opentui (config);
Ink stays the default and the shipping path is untouched.

- _resolve_tui_engine() (env > config > ink); refuses opentui on
  Windows/Termux (no Bun) -> falls back to ink with a notice.
- _make_opentui_argv() -> [bun, src/entry.real.tsx] (no build step).
- _bun_bin() with HERMES_BUN override.
- Branch at top of _make_tui_argv BEFORE _ensure_tui_node (Bun-only host
  must not bootstrap Node).
- Gate _launch_tui NODE_OPTIONS/--max-old-space-size on engine==ink (Bun
  is JSC; the V8 flag errors/ignores).

Verified end-to-end via tmux: real hermes --tui -> Bun -> OpenTUI ->
real Python gateway streamed a real reply. No-flag default still ink.

apps/desktop/src/global.d.ts

@@ -18,10 +18,6 @@ declare global {
       // reaper spares it while its chat is active.
       touchBackend: (profile?: string | null) => Promise<{ ok: boolean }>
       getGatewayWsUrl: (profile?: null | string) => Promise<string>
-      // Open (or focus) a standalone OS window for a single chat session so
-      // the user can work with multiple chats side by side. Returns ok:false
-      // with an error code when the sessionId is empty/invalid.
-      openSessionWindow: (sessionId: string) => Promise<{ ok: boolean; error?: string }>
       getBootProgress: () => Promise<DesktopBootProgress>
       getConnectionConfig: (profile?: null | string) => Promise<DesktopConnectionConfig>
       saveConnectionConfig: (payload: DesktopConnectionConfigInput) => Promise<DesktopConnectionConfig>
@@ -55,9 +51,8 @@ declare global {
       setPreviewShortcutActive?: (active: boolean) => void
       openExternal: (url: string) => Promise<void>
       fetchLinkTitle: (url: string) => Promise<string>
-      sanitizeWorkspaceCwd: (cwd?: null | string) => Promise<{ cwd: string; sanitized: boolean }>
       settings: {
-        getDefaultProjectDir: () => Promise<{ defaultLabel: string; dir: null | string; resolvedCwd: string }>
+        getDefaultProjectDir: () => Promise<{ defaultLabel: string; dir: null | string }>
         pickDefaultProjectDir: () => Promise<{ canceled: boolean; dir: null | string }>
         setDefaultProjectDir: (dir: null | string) => Promise<{ dir: null | string }>
       }
@@ -75,10 +70,6 @@ declare global {
       }
       onClosePreviewRequested?: (callback: () => void) => () => void
       onOpenUpdatesRequested?: (callback: () => void) => () => void
-      onDeepLink?: (
-        callback: (payload: { kind: string; name: string; params: Record<string, string> }) => void,
-      ) => () => void
-      signalDeepLinkReady?: () => Promise<{ ok: boolean }>
       onWindowStateChanged?: (callback: (payload: HermesWindowState) => void) => () => void
       onPreviewFileChanged: (callback: (payload: HermesPreviewFileChanged) => void) => () => void
       onBackendExit: (callback: (payload: BackendExit) => void) => () => void
@@ -101,40 +92,10 @@ declare global {
         summary: () => Promise<DesktopUninstallSummary>
         run: (mode: DesktopUninstallMode) => Promise<DesktopUninstallResult>
       }
-      themes: {
-        // Download a VS Code Marketplace extension and return the raw color
-        // theme files it contributes. The renderer converts + persists them.
-        fetchMarketplace: (id: string) => Promise<DesktopMarketplaceThemeResult>
-        // Search the Marketplace for color-theme extensions. An empty query
-        // returns the most-installed themes.
-        searchMarketplace: (query: string) => Promise<DesktopMarketplaceSearchItem[]>
-      }
     }
   }
 }
 
-export interface DesktopMarketplaceSearchItem {
-  extensionId: string
-  displayName: string
-  publisher: string
-  description: string
-  installs: number
-}
-
-export interface DesktopMarketplaceThemeFile {
-  label: string
-  /** VS Code's `uiTheme` for this entry (vs-dark / vs / hc-black). */
-  uiTheme?: string
-  /** Raw theme JSON (JSONC) text, parsed + converted by the renderer. */
-  contents: string
-}
-
-export interface DesktopMarketplaceThemeResult {
-  extensionId: string
-  displayName: string
-  themes: DesktopMarketplaceThemeFile[]
-}
-
 export interface HermesTerminalSession {
   cwd: string
   id: string