Improve GCP Cloud Run deployment documentation

docs/how-to/deploy/cloud-hosts/gcp-cloud-run.mdx

@@ -45,22 +45,192 @@ The only required environment variable is `PDP_API_KEY`, which is the API key th
 See [Get your API Key](/api/api-with-cli) for more information.
 Note that you can and should set the environment variables from a secret, using your selected secret store provider.
 ![Environment Variables](/img/deployments/gcp/5.png)
-
+:::important
+Use an Environment-level API key (not Project or Org key) for Cloud Run deployments
+:::
 ### 6. Ready to deploy !
 
 Now, we are ready to deploy the PDP.
 Click on the "Create" button to deploy the PDP.
 You can see the logs of the deployment in the "Logs" tab, and if the deployment succeeded, you will see the URL of the PDP in the top section of the Cloud Run service.
 ![Deploy](/img/deployments/gcp/6.png)
 
-## YAML file
-
-We shared the YAML file that we used to deploy the PDP on GCP Cloud Run.
-Take a look at the following [Deployments Github Repository](https://github.com/permitio/permit-pdp-deployments-examples/blob/main/gcp/cloud-run.yaml)
-
 :::info Signal 6 in Cloud Run
 A common misconfiguration issue that can be encountered when deploying the PDP to Google Cloud Run is  having the platform unexpectedly terminate the PDP container with a Signal 6 (SIGABRT). This issue stems from Cloud Run's CPU allocation settings, which allow background task processes, such as the PDP, to release CPU resources when idle. Consequently, this results in the container's termination due to insufficient CPU availability.
 To address this issue and ensure uninterrupted service, we recommend adding the `run.googleapis.com/cpu-throttling: false` annotation in the YAML configuration.
 
 For a deeper understanding of CPU allocation settings in Cloud Run and how they impact your applications, please refer to the following documentation: [Cloud Run CPU Allocation Settings](https://cloud.google.com/run/docs/configuring/cpu-allocation).
-:::
+:::
+
+## YAML file
+
+We shared the YAML file that we used to deploy the PDP on GCP Cloud Run.
+Take a look at the following [Deployments Github Repository](https://github.com/permitio/permit-pdp-deployments-examples/blob/main/gcp/cloud-run.yaml)
+
+### Known-Good Reference Deployment (YAML / CLI)
+
+The following configuration is known to work on Cloud Run and addresses autoscaling, CPU throttling, startup probes, and environment variables appropriately.
+
+##### Prerequisites
+
+- gcloud installed and authenticated
+- Cloud Run and Secret Manager APIs enabled
+- Permit Environment API Key stored in Secret Manager
+
+##### Step 1 — Enable Required APIs
+```bash
+gcloud services enable secretmanager.googleapis.com
+gcloud services enable run.googleapis.com
+```
+
+##### Step 2: Create a Secret for the API Key
+Store your Permit API key securely in GCP Secret Manager:
+```bash
+echo -n "YOUR_PERMIT_API_KEY" | gcloud secrets create permit-pdp-api-key \
+  --data-file=- \
+  --replication-policy=automatic
+```
+
+##### Step 3: Grant Secret Access to the Service Account
+
+Get your default compute service account and grant it access to the secret:
+
+```bash
+# Get the service account email
+SERVICE_ACCOUNT=$(gcloud iam service-accounts list --format="value(email)" | grep compute)
+
+# Grant secret access
+gcloud secrets add-iam-policy-binding permit-pdp-api-key \
+  --member="serviceAccount:${SERVICE_ACCOUNT}" \
+  --role="roles/secretmanager.secretAccessor"
+```
+
+##### Step 4: Create the Cloud Run Service YAML
+
+Create a file named `permit-pdp-service.yaml`:
+```yaml
+apiVersion: serving.knative.dev/v1
+kind: Service
+metadata:
+  name: permit-pdp
+  labels:
+    cloud.googleapis.com/location: us-central1
+  annotations:
+    run.googleapis.com/client-name: cloud-console
+    run.googleapis.com/ingress: all
+    run.googleapis.com/ingress-status: all
+spec:
+  template:
+    metadata:
+      labels:
+        run.googleapis.com/startupProbeType: Default
+      annotations:
+        run.googleapis.com/cpu-throttling: "false"
+        run.googleapis.com/client-name: cloud-console
+        autoscaling.knative.dev/minScale: "1"
+        autoscaling.knative.dev/maxScale: "10"
+    spec:
+      containerConcurrency: 80
+      timeoutSeconds: 300
+      serviceAccountName: YOUR_SERVICE_ACCOUNT_EMAIL
+      containers:
+        - image: permitio/pdp-v2:latest
+          ports:
+            - name: http1
+              containerPort: 7000
+          env:
+            - name: PDP_API_KEY
+              valueFrom:
+                secretKeyRef:
+                  key: latest
+                  name: permit-pdp-api-key
+          resources:
+            limits:
+              cpu: 1000m
+              memory: 512Mi
+          startupProbe:
+            timeoutSeconds: 240
+            periodSeconds: 240
+            failureThreshold: 1
+            tcpSocket:
+              port: 7000
+  traffic:
+    - percent: 100
+      latestRevision: true
+```
+
+**Important Configuration Notes:**
+
+| Setting | Value | Purpose |
+|---------|-------|---------|
+| `run.googleapis.com/cpu-throttling` | `"false"` | Prevents SIGABRT errors by keeping CPU allocated |
+| `autoscaling.knative.dev/minScale` | `"1"` | Avoids cold starts that cause authorization failures |
+| `containerPort` | `7000` | Default PDP port |
+| `startupProbe.timeoutSeconds` | `240` | Allows time for initial policy sync |
+
+##### Step 5: Deploy the Service
+
+```bash
+gcloud run services replace permit-pdp-service.yaml --region=us-central1
+```
+
+##### Step 6: Allow Public Access (Optional)
+
+If you need unauthenticated access to the PDP:
+
+```bash
+gcloud run services add-iam-policy-binding permit-pdp \
+  --region=us-central1 \
+  --member="allUsers" \
+  --role="roles/run.invoker"
+```
+
+##### Step 7: Verify the Deployment
+
+Check the health endpoint:
+
+```bash
+# Get the service URL
+SERVICE_URL=$(gcloud run services describe permit-pdp --region=us-central1 --format="value(status.url)")
+
+# Check health
+curl ${SERVICE_URL}/health
+```
+Expected response:
+```json
+{
+  "components": {
+    "horizon": {
+      "details": {
+        "direct_check": "success",
+        "watchdog": "error"
+      },
+      "error": null,
+      "status": "ok"
+    },
+    "opa": {
+      "error": null,
+      "status": "ok"
+    }
+  },
+  "status": "ok"
+}
+```
+##### Endpoints
+
+Once deployed, your PDP exposes:
+
+- **Health Check**: `https://YOUR_SERVICE_URL/health`
+- **Authorization**: `https://YOUR_SERVICE_URL/allowed`
+
+
+##### Troubleshooting:
+<div style={{ marginTop: '4px' }} />
+###### Signal 6 (SIGABRT) Errors
+Ensure `run.googleapis.com/cpu-throttling: "false"` is set in your annotations.
+
+###### Cold Start Authorization Failures
+Ensure `autoscaling.knative.dev/minScale: "1"` to keep at least one instance running.
+
+###### Quota Errors
+Reduce `autoscaling.knative.dev/maxScale` if you hit CPU/memory quota limits.