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/utils/rate-limiter.ts

@@ -2,17 +2,22 @@ import PQueue from 'p-queue';
 import type { Config } from '../config/index.js';
 import type { Logger } from './logger.js';
 
+const DEFAULT_HOUR_WINDOW_MS = 3600000;
+
 export class RateLimiter {
   private queue: PQueue;
   private lastMessageTime: number = 0;
   private messagesThisHour: number = 0;
   private hourStartTime: number = Date.now();
+  private readonly hourWindowMs: number;
 
   constructor(
     private config: Config,
-    private logger: Logger
+    private logger: Logger,
+    hourWindowMs: number = DEFAULT_HOUR_WINDOW_MS,
   ) {
     this.queue = new PQueue({ concurrency: 1 });
+    this.hourWindowMs = hourWindowMs;
   }
 
   async throttle<T>(fn: () => Promise<T>, shouldCount: (result: T) => boolean = () => true): Promise<T> {
@@ -20,7 +25,7 @@ export class RateLimiter {
       const now = Date.now();
 
       // Reset hourly counter if needed
-      if (now - this.hourStartTime > 3600000) {
+      if (now - this.hourStartTime > this.hourWindowMs) {
         this.messagesThisHour = 0;
         this.hourStartTime = now;
         this.logger.debug('Hourly rate limit counter reset');
@@ -28,7 +33,7 @@ export class RateLimiter {
 
       // Check hourly limit
       if (this.messagesThisHour >= this.config.rateLimit.maxMessagesPerHour) {
-        const waitTime = 3600000 - (now - this.hourStartTime);
+        const waitTime = this.hourWindowMs - (now - this.hourStartTime);
         this.logger.info(`Hourly limit reached, waiting ${Math.round(waitTime / 60000)} minutes`);
         await this.sleep(waitTime);
         this.messagesThisHour = 0;
@@ -94,7 +99,7 @@ export class RateLimiter {
     }
 
     // Calculate when the hourly counter resets
-    const hourlyResetAt = this.hourStartTime + 3600000;
+    const hourlyResetAt = this.hourStartTime + this.hourWindowMs;
 
     // Check if hourly limit is reached
     const isHourlyLimitReached = this.messagesThisHour >= maxMessages;