fix: send both Espo-Authorization and X-Api-Key for opcache clear

The platform stores API keys as base64-encoded Espo-Authorization,
not raw API keys. Send both headers so opcache-clear.php can validate.

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

server.py

@@ -311,7 +311,7 @@ def _clear_opcache(customer, espo_url, api_key):
     try:
         oc_req = urllib.request.Request(
             f'{espo_url}/opcache-clear.php',
-            headers={'X-Api-Key': api_key},
+            headers={'Espo-Authorization': api_key, 'X-Api-Key': api_key},
             method='GET',
         )
         oc_resp = urllib.request.urlopen(oc_req, context=SSL_CTX, timeout=10)