chore(brand): rename the product to ReplyPier

The upstream project name is gone from code, assets, docs and build
output: brand strings, domains (replypier.site and its app/api/docs/help
subdomains), env prefixes, image and network names, the widget's public
JS API (window.ReplyPier, replypierId/BaseUrl/Config/Token), CSS tokens
(--rp-*), file and directory names, and the WordPress plugin package.

- widget loader is now webclient/replypier.min.js; both bundles rebuilt
  from source (backend/assets/widget.{js,css}, frontend/public/webclient)
- NOTICE, llms.txt, CONTRIBUTING, HELP_CENTER_INFRA and config.dev.js
  rewritten rather than string-swapped; the demo config no longer ships
  the previous vendor's Firebase/Razorpay/Google keys
- new migration replypier_ai_model_001 adds REPLYPIER to the managed
  AIModelType and rewrites pre-rename rows
- local compose project, database, role and volume renamed; LOCAL_DEPLOY
  documents carrying the old local data over

frontend/scripts/generate-prod-env.ts

@@ -14,9 +14,9 @@ const configContent = `// Runtime configuration - this file gets replaced at con
 // it too; in a page self === window, so window.APP_CONFIG still works.
 self.APP_CONFIG = {
   // API URLs
-  API_URL: "${process.env.VITE_API_URL || 'https://api.chattermate.chat/api/v1'}",
-  WS_URL: "${process.env.VITE_WS_URL || 'wss://api.chattermate.chat'}",
-  WIDGET_URL: "${process.env.VITE_WIDGET_URL || 'https://api.chattermate.chat'}",
+  API_URL: "${process.env.VITE_API_URL || 'https://api.replypier.site/api/v1'}",
+  WS_URL: "${process.env.VITE_WS_URL || 'wss://api.replypier.site'}",
+  WIDGET_URL: "${process.env.VITE_WIDGET_URL || 'https://api.replypier.site'}",
   
   // Firebase Configuration
   FIREBASE_API_KEY: "${process.env.VITE_FIREBASE_API_KEY || ''}",