docs: add Claude AI assistant rules and configuration

Add comprehensive rule documentation for AI-assisted development covering
authentication surfaces, outbound-call safety invariants, and other project
conventions to guide Claude's understanding of critical system behaviors.

pyproject.toml

@@ -32,9 +32,13 @@ dependencies = [
     # HTTP client (for Speaches STT)
     "httpx>=0.28.0",
 
-    # MCP server (3.x — http_app + StaticTokenVerifier)
+    # MCP server (3.x — http_app + ASGI owner guard)
     "fastmcp>=3.0.0",
 
+    # Auth: Casdoor SSO (OAuth code exchange) + RS256 JWT validation
+    "casdoor>=1.0",
+    "pyjwt[crypto]>=2.8",
+
     # Utilities
     "python-slugify>=8.0.0",
 ]
@@ -47,6 +51,8 @@ dev = [
     "httpx>=0.28.0",
     "ruff>=0.8.0",
     "aiosqlite>=0.22.0",
+    # Mint RS256 JWTs in tests without a live Casdoor
+    "cryptography>=42.0",
 ]
 
 [tool.setuptools.packages.find]