Restructure chat service, web routes, and add test suite

Split monolithic chat service into modular structure with Matrix client
support, extract web server into per-resource route modules, introduce
bootstrap/main-loop separation, and add comprehensive vitest coverage
across services, repositories, and utilities. Adds project docs and
CLAUDE.md agent instructions.

src/web/context.ts

@@ -0,0 +1,58 @@
+import type { Logger } from '../utils/logger.js';
+import type { Config } from '../config/index.js';
+import type {
+  PostsRepository,
+  MessagesRepository,
+  SuccessfulMessagesRepository,
+} from '../database/repositories.js';
+import type { ChatService } from '../services/chat.js';
+import type { MediaService } from '../services/media.js';
+import type { MediaSyncService } from '../services/media-sync.js';
+import type { ResponseCheckerService } from '../services/response-checker.js';
+import type { RateLimiter } from '../utils/rate-limiter.js';
+import type { OpenRouterClient } from '../ai/openrouter.js';
+import type { StrategySelector } from '../services/strategy-selector.js';
+import type { BrowserClient } from '../browser/client.js';
+import type { ActivityLog } from './activity-log.js';
+import type { LogBroadcaster } from './log-broadcaster.js';
+import type { RuntimeConfig } from './types.js';
+
+/** Bag of everything the route modules might need. */
+export interface WebContext {
+  logger: Logger;
+  config: Config;
+  runtimeConfig: RuntimeConfig;
+  activity: ActivityLog;
+  broadcaster: LogBroadcaster;
+
+  repos: {
+    posts: PostsRepository;
+    messages: MessagesRepository;
+    successful: SuccessfulMessagesRepository;
+  };
+
+  services: {
+    chat?: ChatService;
+    media?: MediaService;
+    mediaSync?: MediaSyncService;
+    responseChecker?: ResponseCheckerService;
+    rateLimiter?: RateLimiter;
+    ai?: OpenRouterClient;
+    strategySelector?: StrategySelector;
+    browser?: BrowserClient;
+  };
+
+  /** Bot pause/resume toggle read by the main loop. */
+  getBotRunning(): boolean;
+  setBotRunning(running: boolean): void;
+
+  /** Mirrored count for the dashboard's `messagesThisHour` widget. */
+  getMessagesThisHour(): number;
+
+  /**
+   * Callback invoked when the dashboard mutates `runtimeConfig`.
+   * Wrapped in a getter so callers see the latest value — it can be installed
+   * after the WebContext is constructed.
+   */
+  getOnConfigChange(): ((config: RuntimeConfig) => void) | null;
+}