fix: skip cookie auth check in CLI and lifespan when OAuth is enabled

Both cli_main.ensure_authentication_ready() and auth_lifespan validate
the LinkedIn cookie profile, causing exit(1) on Cloud Run where no
profile exists. Skip both when OAuth mode is active.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 5queezer

linkedin_mcp_server/cli_main.py

@@ -339,9 +339,10 @@ def main() -> None:
 
         logger.debug(f"Server configuration: {config}")
 
-        # Phase 1: Ensure Authentication is Ready
+        # Phase 1: Ensure Authentication is Ready (skip for OAuth — no cookie profile needed)
         try:
-            ensure_authentication_ready()
+            if not (config.server.oauth and config.server.oauth.enabled):
+                ensure_authentication_ready()
             if config.is_interactive:
                 print("✅ Authentication ready")
             logger.info("Authentication ready")