Revert "Make Smart New Tab launcher the default (remove experimental flag) (#4834)"

This reverts commit c32e2dc7cb.

src/shared/constants.ts

@@ -306,6 +306,7 @@ export function getDefaultSettings(homedir: string): GlobalSettings {
     experimentalTerminalAttention: false,
     experimentalCompactWorktreeCards: false,
     experimentalWorktreeSymlinks: false,
+    experimentalUnifiedNewTabLauncher: false,
     // Why: local desktop remains the default server until the user explicitly
     // selects a saved runtime environment.
     activeRuntimeEnvironmentId: null,

src/shared/telemetry-events.ts

@@ -278,6 +278,7 @@ export const SETTINGS_CHANGED_WHITELIST = [
   'experimentalActivity',
   'experimentalTerminalAttention',
   'experimentalWorktreeSymlinks',
+  'experimentalUnifiedNewTabLauncher',
   'geminiCliOAuthEnabled'
 ] as const satisfies readonly BooleanGlobalSettingsKey[]
 export const settingsChangedKeySchema = z.enum(SETTINGS_CHANGED_WHITELIST)

src/shared/types.ts

@@ -2266,7 +2266,9 @@ export type GlobalSettings = {
    *  configuration surface and edge cases (conflicts with existing paths,
    *  cleanup on worktree delete) are still being worked out. */
   experimentalWorktreeSymlinks: boolean
-
+  /** Experimental: replaces the New Tab menu's static preview row with a
+   *  command-style launcher for terminals, detected agents, URLs, and files. */
+  experimentalUnifiedNewTabLauncher: boolean
   /** Active non-local runtime environment for client-routed RPC. `null`
    *  preserves the current local desktop behavior. */
   activeRuntimeEnvironmentId?: string | null