fix: normalize YouTube proxy URL and support dashboard fields

Rewrite https proxy URLs to http, allow HOST/PORT/USER/PASSWORD env vars,
and surface clearer errors when proxies fail on the wrong port.

Co-authored-by: Cursor <cursoragent@cursor.com>

server/settings.py

@@ -19,8 +19,13 @@ class Settings(BaseSettings):
     app_version: str = "1.0.0"
 
     # YouTube transcript proxy (optional — for IP blocks)
-    # Single URL used for HTTP+HTTPS, e.g. http://user:pass@host:port
+    # Option A: full URL — MUST include port, use http:// (not https://)
     youtube_proxy: str = ""
+    # Option B: dashboard fields (Webshare etc.) — combined into a proxy URL
+    youtube_proxy_host: str = ""
+    youtube_proxy_port: int = 0
+    youtube_proxy_user: str = ""
+    youtube_proxy_password: str = ""
     # Webshare rotating residential (paid package — NOT free "Proxy Server" tier)
     webshare_proxy_username: str = ""
     webshare_proxy_password: str = ""