refactor: consolidate ~70 scattered constants into 6 new config files (phase 6)

Create 6 domain-focused config files in src/config/ to centralize operational
tuning knobs that were scattered across 15+ source files:

- server-timing.ts: SSE batching, state debounce, scheduled runs, error recovery
- auth-config.ts: session TTL, rate limits, hook timeout
- tunnel-config.ts: QR token rotation, tunnel process lifecycle
- terminal-limits.ts: input length, terminal cols/rows, session name
- ai-defaults.ts: AI model string, idle/plan context limits
- team-config.ts: poll interval, cache sizes

Eliminates all cross-file duplicates:
- AI model string: 5 occurrences → 1 (config only)
- STATS_COLLECTION_INTERVAL_MS: 2 → 1
- timeout: 10000 in hooks-config: 6 → 0 (now HOOK_TIMEOUT_MS)
- MAX_TRACKED_AGENTS shadow: removed, imports from map-limits

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

src/team-watcher.ts

@@ -17,12 +17,7 @@ import { watch as chokidarWatch, type FSWatcher as ChokidarWatcher } from 'choki
 
 import type { TeamConfig, TeamMember, TeamTask, InboxMessage } from './types.js';
 import { LRUMap } from './utils/lru-map.js';
-
-// ========== Constants ==========
-
-const POLL_INTERVAL_MS = 30000;
-const MAX_CACHED_TEAMS = 50;
-const MAX_CACHED_TASKS = 200;
+import { TEAM_POLL_INTERVAL_MS, MAX_CACHED_TEAMS, MAX_CACHED_TASKS } from './config/team-config.js';
 
 // ========== TeamWatcher Class ==========
 
@@ -52,7 +47,7 @@ export class TeamWatcher extends EventEmitter {
   start(): void {
     if (this.pollTimer) return;
     this.poll();
-    this.pollTimer = setInterval(() => this.poll(), POLL_INTERVAL_MS);
+    this.pollTimer = setInterval(() => this.poll(), TEAM_POLL_INTERVAL_MS);
     this.setupFsWatchers();
   }