fix: Use tcpSocket probe instead of httpGet for MCP endpoint

MCP streamable-http transport returns 406 on GET requests.
Switch to tcpSocket probe for readiness/liveness checks.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

k8s/deployment.yaml

@@ -35,14 +35,12 @@ spec:
             - name: LOG_LEVEL
               value: "INFO"
           readinessProbe:
-            httpGet:
-              path: /mcp
+            tcpSocket:
               port: 8000
             initialDelaySeconds: 5
             periodSeconds: 10
           livenessProbe:
-            httpGet:
-              path: /mcp
+            tcpSocket:
               port: 8000
             initialDelaySeconds: 10
             periodSeconds: 30