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

design/brand-refresh/README.md

@@ -18,14 +18,14 @@
 
 - Browser icon: `frontend/public/favicon.svg`; duplicate `frontend/public/assets/favicon.svg`; ICO fallbacks at both locations.
 - Brand mark: `frontend/src/assets/logo.svg`, `frontend/public/images/logo.svg`, `frontend/public/assets/images/logo.svg`, `logo_dark.svg`.
-- Footer marks: shared `frontend/src/components/common/BrandMark.vue`; `frontend/src/webclient/chattermate.js` imports the same source SVG for its error footer.
+- Footer marks: shared `frontend/src/components/common/BrandMark.vue`; `frontend/src/webclient/replypier.js` imports the same source SVG for its error footer.
 - Preset portraits: 12 PNGs in `frontend/src/assets/avatars/avatar-*.png`; selected through `AgentDetail.vue`.
 - Paper-craft avatars: ten SVGs under `frontend/src/assets/avatars/paper-*.svg`; loaded by `frontend/src/utils/orb.ts` under the original stored variant indexes. Old generated data URIs are refreshed from avatar metadata at render time. Uploaded photos remain unchanged.
 - Additional candidates: PWA/install icons, default user/robot and role avatars, login/signup illustration. Third-party integration logos should retain official identities.
 
 ## Design constraints
 
-Use existing ink/porcelain foundation: paper #F4F1EB, ink #16171A, vermilion #B23A22, celadon #2E6A5C, brass #8A6326. Keep 16px brand marks simple and readable. No change to customer-uploaded images or unrelated UI. Visible product naming currently mixes ReplyPier and ChatterMate; do not infer a full rename from the asset request.
+Use existing ink/porcelain foundation: paper #F4F1EB, ink #16171A, vermilion #B23A22, celadon #2E6A5C, brass #8A6326. Keep 16px brand marks simple and readable. No change to customer-uploaded images or unrelated UI. Product naming is ReplyPier throughout (UI, code identifiers, docs); the old upstream name was purged in one pass, so any remaining trace is a bug worth fixing.
 
 ## Concepts