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

backend/tests/services/test_faq_article_import.py

@@ -1,5 +1,5 @@
 """
-Copyright 2024-2026 ChatterMate
+Copyright 2024-2026 ReplyPier
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -165,7 +165,7 @@ def test_fetch_article_converts_markdown_strips_chrome_and_collects_images():
     # Link absolutized (same-site remapping happens later, in the import job).
     assert "[pricing](https://help.example.com/pricing)" in article.markdown
     # Real image collected as placeholder; data: image reduced to alt text.
-    assert "cm-pending-image://0.img" in article.markdown
+    assert "rp-pending-image://0.img" in article.markdown
     assert len(article.pending_images) == 1
     assert "base64" not in article.markdown
     # Help-center chrome stripped: no Chatwoot footer, breadcrumb or metadata.