[kimi] Add CORS config for Matrix frontend origin (#679) (#741)

src/dashboard/app.py

@@ -10,6 +10,7 @@ Key improvements:
 import asyncio
 import json
 import logging
+import re
 from contextlib import asynccontextmanager
 from pathlib import Path
 
@@ -520,17 +521,40 @@ app = FastAPI(
 
 
 def _get_cors_origins() -> list[str]:
-    """Get CORS origins from settings, rejecting wildcards in production."""
-    origins = settings.cors_origins
+    """Get CORS origins from settings, rejecting wildcards in production.
+
+    Adds matrix_frontend_url when configured. Always allows Tailscale IPs
+    (100.x.x.x range) for development convenience.
+    """
+    origins = list(settings.cors_origins)
+
+    # Strip wildcards in production (security)
     if "*" in origins and not settings.debug:
         logger.warning(
             "Wildcard '*' in CORS_ORIGINS stripped in production — "
             "set explicit origins via CORS_ORIGINS env var"
         )
         origins = [o for o in origins if o != "*"]
+
+    # Add Matrix frontend URL if configured
+    if settings.matrix_frontend_url:
+        url = settings.matrix_frontend_url.strip()
+        if url and url not in origins:
+            origins.append(url)
+            logger.debug("Added Matrix frontend to CORS: %s", url)
+
     return origins
 
 
+# Pattern to match Tailscale IPs (100.x.x.x) for CORS origin regex
+_TAILSCALE_IP_PATTERN = re.compile(r"^https?://100\.\d{1,3}\.\d{1,3}\.\d{1,3}(?::\d+)?$")
+
+
+def _is_tailscale_origin(origin: str) -> bool:
+    """Check if origin is a Tailscale IP (100.x.x.x range)."""
+    return bool(_TAILSCALE_IP_PATTERN.match(origin))
+
+
 # Add dedicated middleware in correct order
 # 1. Logging (outermost to capture everything)
 app.add_middleware(RequestLoggingMiddleware, skip_paths=["/health"])
@@ -552,6 +576,7 @@ app.add_middleware(
 app.add_middleware(
     CORSMiddleware,
     allow_origins=_get_cors_origins(),
+    allow_origin_regex=r"https?://100\.\d{1,3}\.\d{1,3}\.\d{1,3}(:\d+)?",
     allow_credentials=True,
     allow_methods=["GET", "POST", "PUT", "DELETE", "OPTIONS"],
     allow_headers=["Content-Type", "Authorization"],