Add experimental Activity page (#1703)

src/shared/constants.ts

@@ -233,6 +233,7 @@ export function getDefaultSettings(homedir: string): GlobalSettings {
     // Why: off by default — opt-in cosmetic joke feature. Leaving the default
     // false keeps the overlay unmounted for users who never enable it.
     experimentalPet: false,
+    experimentalActivity: false,
     experimentalWorktreeSymlinks: false,
     // Why: hydrate an empty default so the renderer's optional-chained reads
     // (`settings?.githubProjects?.activeProject`) land on a stable shape

src/shared/telemetry-events.ts

@@ -174,6 +174,7 @@ export const SETTINGS_CHANGED_WHITELIST = [
   'openLinksInApp',
   'experimentalMobile',
   'experimentalPet',
+  'experimentalActivity',
   'experimentalWorktreeSymlinks',
   'geminiCliOAuthEnabled'
 ] as const satisfies readonly BooleanGlobalSettingsKey[]

src/shared/types.ts

@@ -1269,6 +1269,10 @@ export type GlobalSettings = {
   /** Legacy persisted key from before the sidekick -> pet rename. Read only
    *  during migration; new writes use experimentalPet. */
   experimentalSidekick?: boolean
+  /** Experimental: Slack-style Activity page that groups agent/worktree status
+   *  events by worktree. Opt-in while the UI and backend event model are still
+   *  being refined. */
+  experimentalActivity: boolean
   /** Experimental: when creating a worktree, automatically symlink a
    *  user-configured set of files/folders from the primary checkout (e.g.
    *  `.env`, `node_modules`) into the new worktree. Opt-in while the