fix(agent-dashboard): persist acknowledgedAgentsByPaneKey across restart

Without this, agent rows the user already visited come back bold every relaunch now that the rows themselves survive restart (per docs/agent-dashboard-retention-restart.md). Hydrate sanitizes input field-by-field (rejects null/non-object/array, prototype-pollution keys, non-finite/non-positive values) and applies a 7-day TTL paralleling HYDRATE_MAX_AGE_MS in agent-hooks/server.ts so hard-quit/crash paths can't grow the persisted map forever.

Co-authored-by: Orca <help@stably.ai>

src/shared/constants.ts

@@ -292,7 +292,8 @@ export function getDefaultUIState(): PersistedUIState {
     statusBarVisible: true,
     dismissedUpdateVersion: null,
     lastUpdateCheckAt: null,
-    trustedOrcaHooks: {}
+    trustedOrcaHooks: {},
+    acknowledgedAgentsByPaneKey: {}
   }
 }
 

src/shared/types.ts

@@ -1461,6 +1461,15 @@ export type PersistedUIState = {
   /** Once the user has seen the "your sessions won't be interrupted"
    *  reassurance card, we never show it again. */
   updateReassuranceSeen?: boolean
+  /** Per-paneKey "user has visited this row" timestamps, used by the inline
+   *  agents list to mute rows the user has already seen. Persisted because
+   *  agent rows themselves now survive restart (see
+   *  docs/agent-dashboard-retention-restart.md); without persisting acks too,
+   *  rows you'd already clicked come back bold on relaunch. Stale entries
+   *  keyed on dead panes are inert: a future paneKey reuse stamps a fresh
+   *  stateStartedAt that beats the old ack via the existing comparison in
+   *  WorktreeCardAgents. Renderer-owned, written through ui:set. */
+  acknowledgedAgentsByPaneKey?: Record<string, number>
   /** URL to navigate to when a new browser tab is opened. Null means blank tab.
    *  Phase 3 will expand this to a full BrowserSessionProfile per workspace. */
   browserDefaultUrl?: string | null