feat: add ask_user interactive user input to frontend

Wire the sidecar user-input-requested protocol event through the main
process, IPC layer, and renderer UI so agents can ask the user
interactive questions with choices and freeform input.

- Add UserInputRequestedEvent and ResolveUserInputCommand to sidecar
  protocol types
- Add resolveUserInput method to SidecarClient and onUserInput callback
  to runTurn
- Create PendingUserInputRecord domain type and add pendingUserInput to
  SessionRecord
- Add handleUserInputRequested and resolveSessionUserInput to
  AryxAppService with handle management
- Register sessions:resolve-user-input IPC channel with preload bridge
- Create UserInputBanner component with choice buttons and freeform
  input
- Integrate UserInputBanner into ChatPane with header indicator

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/preload/index.ts

@@ -36,6 +36,7 @@ const api: ElectronApi = {
   sendSessionMessage: (input) => ipcRenderer.invoke(ipcChannels.sendSessionMessage, input),
   cancelSessionTurn: (input) => ipcRenderer.invoke(ipcChannels.cancelSessionTurn, input),
   resolveSessionApproval: (input) => ipcRenderer.invoke(ipcChannels.resolveSessionApproval, input),
+  resolveSessionUserInput: (input) => ipcRenderer.invoke(ipcChannels.resolveSessionUserInput, input),
   updateSessionModelConfig: (input) =>
     ipcRenderer.invoke(ipcChannels.updateSessionModelConfig, input),
   querySessions: (input) => ipcRenderer.invoke(ipcChannels.querySessions, input),