Add KEDA scaling, Grafana dashboard, Chaos Mesh, Locust, and deploy workflow

Complete stages 5-9 of the implementation plan:
- KEDA ScaledObjects for all 3 worker deployments (queue-depth autoscaling)
- Grafana dashboard JSON (7 panels, 5s refresh for live demo)
- Chaos Mesh experiments (pod-kill, network-delay, cpu-stress)
- Locust load test with 4 weighted task types
- GitHub Actions deploy workflow (ACR build + AKS deploy)
- Added workflow_call trigger to ci.yml for reuse by deploy workflow

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

Author: johnmathews

.github/workflows/ci.yml

@@ -5,6 +5,7 @@ on:
     branches: [main]
   pull_request:
     branches: [main]
+  workflow_call:
 
 jobs:
   lint:

.github/workflows/deploy.yml

@@ -0,0 +1,81 @@
+name: Deploy to AKS
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "src/**"
+      - "k8s/**"
+  workflow_dispatch:
+
+concurrency:
+  group: deploy-aks
+  cancel-in-progress: false
+
+jobs:
+  ci:
+    uses: ./.github/workflows/ci.yml
+
+  build-and-deploy:
+    needs: ci
+    runs-on: ubuntu-latest
+    environment: production
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Log in to Azure
+        uses: azure/login@v2
+        with:
+          creds: ${{ secrets.AZURE_CREDENTIALS }}
+
+      - name: Build and push gateway image to ACR
+        run: |
+          az acr build \
+            -r acrdocumentstream \
+            -t gateway:${{ github.sha }} \
+            -t gateway:latest \
+            -f src/gateway/Dockerfile .
+
+      - name: Build and push worker image to ACR
+        run: |
+          az acr build \
+            -r acrdocumentstream \
+            -t worker:${{ github.sha }} \
+            -t worker:latest \
+            -f src/worker/Dockerfile .
+
+      - name: Set AKS context
+        run: |
+          az aks get-credentials \
+            -n documentstream-aks \
+            -g documentstream-rg \
+            --overwrite-existing
+
+      - name: Apply K8s manifests
+        run: kubectl apply -k k8s/base/
+
+      - name: Update deployment image tags
+        run: |
+          kubectl set image deployment/gateway \
+            gateway=acrdocumentstream.azurecr.io/gateway:${{ github.sha }} \
+            -n documentstream
+
+          kubectl set image deployment/extract-worker \
+            extract-worker=acrdocumentstream.azurecr.io/worker:${{ github.sha }} \
+            -n documentstream
+
+          kubectl set image deployment/classify-worker \
+            classify-worker=acrdocumentstream.azurecr.io/worker:${{ github.sha }} \
+            -n documentstream
+
+          kubectl set image deployment/store-worker \
+            store-worker=acrdocumentstream.azurecr.io/worker:${{ github.sha }} \
+            -n documentstream
+
+      - name: Wait for rollouts
+        run: |
+          kubectl rollout status deployment/gateway -n documentstream --timeout=120s
+          kubectl rollout status deployment/extract-worker -n documentstream --timeout=120s
+          kubectl rollout status deployment/classify-worker -n documentstream --timeout=120s
+          kubectl rollout status deployment/store-worker -n documentstream --timeout=120s