Add debug logging for complete authorization URL

Shows the exact GET request URL being sent to IndieLogin.com's
/authorize endpoint, including all query parameters in their
encoded form. This helps debug authentication flow issues.

- Added debug log after auth_url construction in initiate_login()
- Logs complete URL with all parameters before redirect
- Version remains 0.9.1 (debugging enhancement only)

starpunk/auth.py

@@ -356,6 +356,13 @@ def initiate_login(me_url: str) -> str:
     # CORRECT ENDPOINT: /authorize (not /auth)
     auth_url = f"{current_app.config['INDIELOGIN_URL']}/authorize?{urlencode(params)}"
 
+    # Log the complete authorization URL for debugging
+    current_app.logger.debug(
+        "Auth: Complete authorization URL (GET request):\n"
+        "  %s",
+        auth_url
+    )
+
     current_app.logger.info(f"Auth: Authentication initiated for {me_url}")
 
     return auth_url