refactor: pass 3 — extract helpers, split long functions, deduplicate patterns

Backend:
- subagent-watcher: split 176L processEntry() into 5 focused methods; extract
  _resolveDescription() deduplicating 3 call sites for description acquisition
- bash-tool-parser: split 152L processCleanLine() into 4 handlers; extract
  _createActiveTool() factory and _scheduleAutoRemove() helper
- session: extract _setupOrAttachMuxSession() deduplicating ~80L between
  startInteractive/startShell; extract _handleTerminalOutput()
- respawn-controller: split 180L handleTerminalData() into 3 detection layers;
  data-driven validation loop replacing 9 individual calls
- plan-orchestrator: extract _extractJsonFromResponse(), _emitAgentFailure(),
  _formatResearchSection() helpers
- orchestrator-loop: extract _finalizeTask() unifying task completion/failure;
  _clearTimer() utility for correct clearInterval/clearTimeout dispatch
- ralph-status-parser: config-driven FIELD_PARSERS[] replacing 8 near-identical
  field-matching blocks; split updateCircuitBreaker() into focused handlers
- state-store: extract _mergeWithInitialState() and _resetCircuitBreaker()

Frontend:
- app.js: add _notifySession() helper used by 18 call sites across 5 modules
- panels-ui.js: extract _addActivityEntry() replacing 4 duplicate blocks
- settings-ui.js: extract _updateTunnelUrlRow() deduplicating 2 blocks
- ralph-panel.js, respawn-ui.js: convert to _notifySession()

Routes:
- route-helpers: add toggleService() helper
- system-routes: use toggleService() for watcher toggles; extract collectActiveTokens()
- orchestrator-routes: data-driven EVENT_MAP replacing 10 identical listeners

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/web/route-helpers.ts

@@ -185,6 +185,26 @@ export function sanitizeHookData(data: Record<string, unknown> | null | undefine
   return safeFields;
 }
 
+/**
+ * Toggles a service (watcher/manager) on or off based on an enabled flag.
+ * Logs start/stop to console with the given label. Runs an optional callback after starting.
+ */
+export function toggleService(
+  enabled: boolean,
+  service: { isRunning(): boolean; start(): void; stop(): void },
+  label: string,
+  onStart?: () => void
+): void {
+  if (enabled && !service.isRunning()) {
+    service.start();
+    onStart?.();
+    console.log(`${label} started via settings change`);
+  } else if (!enabled && service.isRunning()) {
+    service.stop();
+    console.log(`${label} stopped via settings change`);
+  }
+}
+
 /**
  * Auto-configure Ralph tracker for a session.
  *