feat: Cloudflare Workers code port (deploy pending)

Refactors source to be Worker-shaped. No live deploy yet — sister deploy plan
runs Atlas provisioning + smoke later.

- wrangler.toml with nodejs_compat_v2, daily UTC 0 cron (= 7am Asia/Ho_Chi_Minh)
- package.json: drop node-telegram-bot-api, node-cron, dotenv, pino,
  pino-pretty; add wrangler devDep; bump to 0.2.0
- src/bot/telegram-api.js: raw fetch wrapper for Telegram Bot API
- src/bot/dispatch.js: per-message dispatcher extracted from polling loop
- src/repository/mongodb.js: memoized MongoClient per warm isolate, typed
  MongoUnavailable error, fast-fail timeouts
- src/repository/store.js: factory binding env once
- All 4 repositories converted to factory shape
- src/api/{apple,google}-scraper.js: take store instead of importing repos
- src/index.js: Worker entry exporting { fetch, scheduled }; webhook validates
  X-Telegram-Bot-Api-Secret-Token; ack-then-waitUntil pattern
- src/scheduler/scheduler.js: trimmed; runDailyCheck only (no node-cron)
- src/config.js, src/logger.js: env-driven, console.log JSON output
- scripts/register-webhook.js: setWebhook + setMyCommands; --dry-run supported
- scripts/check-secret-leaks.js: lint blocks console.log(env.<SECRET>)
- plans/260426-2015-cloudflare-worker-code-port: this code port plan
- plans/260426-2327-cloudflare-deploy-and-smoke: sister deploy plan

Validated via node --check on all 32 source files; lint clean. Real deploy
gates (bundle size, cold-start CPU) run in deploy plan.

package.json

@@ -1,7 +1,7 @@
 {
   "name": "js-store-scraper-bot",
-  "version": "0.1.0",
-  "description": "JavaScript port of store-scraper-bot — Telegram bot for tracking Apple/Google Play app updates.",
+  "version": "0.2.0",
+  "description": "JavaScript port of store-scraper-bot — Telegram bot tracking Apple App Store + Google Play app updates. Deploys to Cloudflare Workers.",
   "type": "module",
   "private": true,
   "engines": {
@@ -9,17 +9,17 @@
   },
   "main": "src/index.js",
   "scripts": {
-    "start": "node src/index.js",
-    "dev": "node --watch src/index.js",
-    "lint": "node --check src/index.js"
+    "dev": "wrangler dev",
+    "deploy": "wrangler deploy && npm run register",
+    "register": "node --env-file=.env.deploy scripts/register-webhook.js",
+    "register:dry": "node --env-file=.env.deploy scripts/register-webhook.js --dry-run",
+    "lint": "node scripts/check-secret-leaks.js"
   },
   "dependencies": {
-    "dotenv": "^16.4.5",
-    "mongodb": "^6.10.0",
-    "node-cron": "^3.0.3",
-    "node-telegram-bot-api": "^0.66.0",
-    "pino": "^9.5.0",
-    "pino-pretty": "^11.3.0"
+    "mongodb": "^6.10.0"
+  },
+  "devDependencies": {
+    "wrangler": "^3.90.0"
   },
   "license": "Apache-2.0"
 }