feat: add OAuth 2.0 support for GSC monitoring

- Updated monitor.py to support both OAuth and Service Account
- Created setup-oauth-local.py for easy local authorization
- Created cronjob-oauth.yaml for OAuth-based deployment
- Updated README with both authentication options
- OAuth is now the recommended method (no key file needed)

scripts/gsc-monitoring/cronjob-oauth.yaml

@@ -0,0 +1,32 @@
+apiVersion: batch/v1
+kind: CronJob
+metadata:
+  name: gsc-monitoring-oauth
+  namespace: manoonoils
+spec:
+  schedule: "0 9 * * *"  # Run daily at 9 AM UTC
+  jobTemplate:
+    spec:
+      template:
+        spec:
+          containers:
+          - name: gsc-monitor
+            image: gcr.io/manoonoils/gsc-monitoring:latest
+            env:
+            - name: GSC_OAUTH_FILE
+              value: /etc/gsc-monitoring/oauth-credentials.json
+            - name: PYTHONUNBUFFERED
+              value: "1"
+            volumeMounts:
+            - name: gsc-oauth-credentials
+              mountPath: /etc/gsc-monitoring
+              readOnly: true
+            - name: logs
+              mountPath: /var/log/gsc-monitoring
+          volumes:
+          - name: gsc-oauth-credentials
+            secret:
+              secretName: gsc-oauth-credentials
+          - name: logs
+            emptyDir: {}
+          restartPolicy: OnFailure