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/app/core/config.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.
@@ -32,16 +32,16 @@ BACKEND_DIR = Path(__file__).resolve().parent.parent.parent
 ENV_FILE = Path(os.getenv("ENV_FILE") or BACKEND_DIR / ".env")
 load_dotenv(ENV_FILE)
 
-DEFAULT_CORS = ["https://chattermate.chat", "http://localhost:5173", "http://localhost:8000"]
+DEFAULT_CORS = ["https://replypier.site", "http://localhost:5173", "http://localhost:8000"]
 
 class Settings(BaseSettings):
-    PROJECT_NAME: str = "ChatterMate"
+    PROJECT_NAME: str = "ReplyPier"
     VERSION: str = "0.1.0"
     API_V1_STR: str = "/api/v1"
 
     # Database
     DATABASE_URL: str = os.getenv(
-        "DATABASE_URL", "postgresql+psycopg://test:test@localhost:5432/chattermate")
+        "DATABASE_URL", "postgresql+psycopg://test:test@localhost:5432/replypier")
     # Redis
     REDIS_URL: str = os.getenv("REDIS_URL", "redis://localhost:6379/0")
     REDIS_ENABLED: bool = os.getenv("REDIS_ENABLED", "false").lower() == "true"
@@ -85,8 +85,8 @@ class Settings(BaseSettings):
     SMTP_PORT: int = int(os.getenv("SMTP_PORT", "587"))
     SMTP_USERNAME: str = os.getenv("SMTP_USERNAME", "your-email@gmail.com")
     SMTP_PASSWORD: str = os.getenv("SMTP_PASSWORD", "your-password")
-    FROM_EMAIL: str = os.getenv("FROM_EMAIL", "noreply@chattermate.chat")
-    FROM_NAME: str = os.getenv("FROM_NAME", "ChatterMate")
+    FROM_EMAIL: str = os.getenv("FROM_EMAIL", "noreply@replypier.site")
+    FROM_NAME: str = os.getenv("FROM_NAME", "ReplyPier")
 
     # Shopify
     SHOPIFY_API_KEY: str = os.getenv("SHOPIFY_API_KEY", "")
@@ -152,7 +152,7 @@ class Settings(BaseSettings):
 
     # S3 Configuration
     S3_FILE_STORAGE: bool = os.getenv("S3_FILE_STORAGE", "false").lower() == "true"
-    S3_BUCKET: str = os.getenv("S3_BUCKET", "chattermate-uploads")
+    S3_BUCKET: str = os.getenv("S3_BUCKET", "replypier-uploads")
     S3_REGION: str = os.getenv("S3_REGION", "us-east-1")
     # None, not "", when unset: boto3 only falls back to its default credential
     # chain (env → shared config → IAM instance/container role) if these are
@@ -256,9 +256,9 @@ class Settings(BaseSettings):
     # to "path" mode.
     HELP_CENTER_PUBLIC_MODE: str = os.getenv("HELP_CENTER_PUBLIC_MODE", "path")
     # Base domain serving {slug}.<base> help centers.
-    HELP_CENTER_BASE_DOMAIN: str = os.getenv("HELP_CENTER_BASE_DOMAIN", "chattermate.help")
+    HELP_CENTER_BASE_DOMAIN: str = os.getenv("HELP_CENTER_BASE_DOMAIN", "help.replypier.site")
     # CNAME target customers point their custom help-center domain at.
-    HELP_CENTER_CNAME_TARGET: str = os.getenv("HELP_CENTER_CNAME_TARGET", "cname.chattermate.chat")
+    HELP_CENTER_CNAME_TARGET: str = os.getenv("HELP_CENTER_CNAME_TARGET", "cname.replypier.site")
     # IPs the CNAME target resolves to — accepted when a provider flattens the
     # CNAME into A/AAAA records (comma-separated).
     HELP_CENTER_TARGET_IPS: frozenset = frozenset(
@@ -273,7 +273,7 @@ class Settings(BaseSettings):
     # Force a context-window size (tokens) for exotic/self-hosted models; 0 = auto.
     FAQ_CONTEXT_TOKENS_OVERRIDE: int = int(os.getenv("FAQ_CONTEXT_TOKENS_OVERRIDE", "0"))
     # Meter FAQ generation credits even for orgs on their own API key
-    # (default: hosted CHATTERMATE model only).
+    # (default: hosted REPLYPIER model only).
     FAQ_METER_OWN_KEY: bool = os.getenv("FAQ_METER_OWN_KEY", "false").lower() == "true"
     FAQ_IMPORT_MAX_PAGE_CHARS: int = int(os.getenv("FAQ_IMPORT_MAX_PAGE_CHARS", "100000"))
     FAQ_IMPORT_FETCH_TIMEOUT: int = int(os.getenv("FAQ_IMPORT_FETCH_TIMEOUT", "30"))