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/channels/own-meta-app.spec.ts

@@ -13,7 +13,7 @@ import {
 // by the dashboard's unit tests.
 
 test.describe('a number or Page from the customer\'s own Meta app', () => {
-  test('a WhatsApp number receives messages: its webhooks are pointed at ChatterMate on connect @channels', async ({ agent, llm, adminApi, request }) => {
+  test('a WhatsApp number receives messages: its webhooks are pointed at ReplyPier on connect @channels', async ({ agent, llm, adminApi, request }) => {
     await llm.script(agent, (s) => s
       .when(/opening hours/i).reply('We are open 9am to 5pm, Monday to Friday.')
       .otherwise().reply('Happy to help!'))