feat(FN-2449): merge fusion/fn-2449

docs/dashboard-guide.md

@@ -44,6 +44,9 @@ Quick Chat is an optional floating panel for fast, project-scoped assistant conv
 - Controlled by the project setting `showQuickChatFAB`
 - Supports agent mentions (`@agent`) and file mentions
 - Uses the same model/provider infrastructure as full Chat view
+- `switchSession()` resumes the existing thread for the selected target (agent-only or agent+model)
+- `startFreshSession()` is the explicit new-thread action and always creates a new persisted session
+- Resume lookups use a targeted session query instead of loading the full active session list first
 
 ## Mailbox View