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

e2e/specs/perf/budgets.spec.ts

@@ -6,7 +6,7 @@ import { test, expect, env, AI_REPLY } from '@e2e'
 
 const KB = 1024
 const BUDGETS = [
-  { file: 'embed loader (chattermate.min.js)', url: `${env.frontendUrl}/webclient/chattermate.min.js`, maxBytes: 60 * KB },
+  { file: 'embed loader (replypier.min.js)', url: `${env.frontendUrl}/webclient/replypier.min.js`, maxBytes: 60 * KB },
   { file: 'widget script (widget.js)', url: `${env.backendUrl}/assets/widget.js`, maxBytes: 500 * KB },
   { file: 'widget styles (widget.css)', url: `${env.backendUrl}/assets/widget.css`, maxBytes: 135 * KB },
 ]