Fix CLI subagent task routing, Ctrl+C cancellation, and session restore reliability

- Construct ServerTask directly for Bedrock CLI subagents so messages route
  correctly without needing a server CreateTask upgrade
- Handle CliAgentUserQuery input type in both request translators, including
  running command context and terminal output
- Add force_cancel_all_streaming_exchanges fallback for when Ctrl+C finds no
  in-flight streams (stuck subagent / unexpected stream end)
- Cancel active conversation on Ctrl+C in agent view compose state
- Skip agent view entry when agent is tagged-in for a running command
- Set root_task_id on Bedrock requests for proper optimistic task upgrade
- Persist app state on will_terminate to avoid losing sessions
- Trust persisted CWD without is_dir() recheck (fixes network mount restore)
- Log warning instead of silently dropping tabs with unreadable root nodes

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src/terminal/view.rs

@@ -6960,6 +6960,11 @@ impl TerminalView {
                 self.agent_view_controller.update(ctx, |controller, ctx| {
                     controller.clear_pending_exit_confirmation(ctx);
                 });
+                // Also cancel any in-progress conversation so that Ctrl+C while
+                // composing a message (or after submitting when the buffer hasn't
+                // cleared yet) properly stops the agent query and returns the
+                // terminal to a ready state.
+                self.cancel_active_conversation_via_status_bar(ctx);
                 return;
             }