Refactor: delete dead code, extract utils, rename files for clarity

- Delete scheduler-mcp.ts (285 lines of dead code, unused)
- Extract loadJson/saveJson to utils.ts (generic utilities)
- Rename auth.ts → whatsapp-auth.ts (more specific)
- Rename scheduler.ts → task-scheduler.ts (more specific)
- Update all references in docs and imports

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -20,8 +20,9 @@ import {
 } from './config.js';
 import { RegisteredGroup, Session, NewMessage } from './types.js';
 import { initDatabase, storeMessage, storeChatMetadata, getNewMessages, getMessagesSince, getAllTasks, getTaskById } from './db.js';
-import { startSchedulerLoop } from './scheduler.js';
+import { startSchedulerLoop } from './task-scheduler.js';
 import { runContainerAgent, writeTasksSnapshot } from './container-runner.js';
+import { loadJson, saveJson } from './utils.js';
 
 const logger = pino({
   level: process.env.LOG_LEVEL || 'info',
@@ -42,22 +43,6 @@ async function setTyping(jid: string, isTyping: boolean): Promise<void> {
   }
 }
 
-function loadJson<T>(filePath: string, defaultValue: T): T {
-  try {
-    if (fs.existsSync(filePath)) {
-      return JSON.parse(fs.readFileSync(filePath, 'utf-8'));
-    }
-  } catch (e) {
-    logger.warn({ filePath, error: e }, 'Failed to load JSON file');
-  }
-  return defaultValue;
-}
-
-function saveJson(filePath: string, data: unknown): void {
-  fs.mkdirSync(path.dirname(filePath), { recursive: true });
-  fs.writeFileSync(filePath, JSON.stringify(data, null, 2));
-}
-
 function loadState(): void {
   const statePath = path.join(DATA_DIR, 'router_state.json');
   const state = loadJson<{ last_timestamp?: string; last_agent_timestamp?: Record<string, string> }>(statePath, {});