v2: SQLite state adapter, admin commands, compact feedback

- Replace in-memory Chat SDK state with SqliteStateAdapter — thread
  subscriptions now persist across restarts
- Add migration 002 for chat_sdk_kv, subscriptions, locks, lists tables
- Handle /clear in agent-runner (reset sessionId) — SDK has
  supportsNonInteractive:false for this command
- Pass /compact, /context, /cost, /files through to SDK as admin commands
- Skip admin commands in follow-up poll so they start fresh queries
- Emit compact_boundary events as user-visible feedback messages
- Pass NANOCLAW_ADMIN_USER_ID and NANOCLAW_ASSISTANT_NAME to containers

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

src/db/migrations/index.ts

@@ -2,6 +2,7 @@ import type Database from 'better-sqlite3';
 
 import { log } from '../../log.js';
 import { migration001 } from './001-initial.js';
+import { migration002 } from './002-chat-sdk-state.js';
 
 export interface Migration {
   version: number;
@@ -9,7 +10,7 @@ export interface Migration {
   up: (db: Database.Database) => void;
 }
 
-const migrations: Migration[] = [migration001];
+const migrations: Migration[] = [migration001, migration002];
 
 export function runMigrations(db: Database.Database): void {
   db.exec(`