chore: repo cleanup + docs for admin API and DB schema (v1.2.8)

- remove stale docs/admin-frontend-spec.md (old Express/EJS admin), unused templates/ (SmartAdmin copy), dead scripts/sync-agents.cjs, committed dev.pid
- add docs/API.md (admin REST API reference) and docs/DATABASE.md (DB schema)
- refresh .env.example: drop stale ADMIN_PORT/SHOP_CONTAINER, add ADMIN_URL, HEALTH_PORT, DEFAULT_LANGUAGE, CHATBOT_API_*
- add npm run lint so Gitea workflows pass
- rebrand web-testing suite from APAW to telegram-shop

tests/package.json

@@ -1,7 +1,7 @@
 {
-  "name": "apaw-web-testing",
+  "name": "telegram-shop-web-testing",
   "version": "2.0.0",
-  "description": "Web application testing suite for APAW - Visual regression, link checking, form testing, console error detection",
+  "description": "Web application testing suite for Telegram Shop - Visual regression, link checking, form testing, console error detection",
   "main": "scripts/visual-test-pipeline.js",
   "scripts": {
     "test": "node scripts/visual-test-pipeline.js",
@@ -19,7 +19,7 @@
     "playwright",
     "kilo-code"
   ],
-  "author": "APAW Team",
+  "author": "Telegram Shop Team",
   "license": "MIT",
   "dependencies": {
     "pixelmatch": "^5.3.0",