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/FEATURES.md

@@ -21,7 +21,7 @@ One row per user journey. Every feature PR adds or updates its row and the spec
 | Widget chat | Email-first agent (gate → chat, person recorded), Ask anything panel, lead capture with no email asked — each also with the first authorization lost | `specs/widget/chat-styles.spec.ts` | P1 | ✅ |
 | Widget chat | Agent wraps up → customer rates the chat → rating stored against the agent | `specs/widget/rating.spec.ts` | P1 | ✅ |
 | Widget chat | A second browser that types a customer's email gets its own empty conversation (the owner keeps theirs), can't rename them or make them a lead, and an address claimed before its owner signs in yields none of their chats | `specs/widget/conversation-ownership.spec.ts` | P1 | ✅ |
-| Widget chat | Scoping keeps a visitor's own conversation: a second tab joins it; a visitor the site signed in finds it in another browser, and after `ChatterMate.identify()` | `specs/widget/conversation-ownership.spec.ts` | P1 | ✅ |
+| Widget chat | Scoping keeps a visitor's own conversation: a second tab joins it; a visitor the site signed in finds it in another browser, and after `ReplyPier.identify()` | `specs/widget/conversation-ownership.spec.ts` | P1 | ✅ |
 | Widget chat | Provider error, provider timeout and malformed reply each end in an apology; the next message works | `specs/widget/ai-failures.spec.ts` | P1 | ✅ |
 | Human handover | AI hands over → contact form → agent takes over → two-way messages → the AI stays silent | `specs/handover/handover.spec.ts` | P1 | ✅ |
 | Human handover | After hours, or nobody online: the chat waits in the team's queue with a reply that says so | `specs/handover/after-hours.org.spec.ts`, `nobody-online.spec.ts` | P1 | ✅ |