ci: add database migration automation workflow (API-AI-079)

- 3-stage: validate → dry-run → deploy-migration
- validate: prisma format check, client generation verification
- dry-run: MySQL service container, db push + migrate deploy + status
- deploy-migration: manual trigger, SSH migrate deploy with pre/post status
- Triggered on schema.prisma or migrations/** changes

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.github/workflows/migration.yml

@@ -0,0 +1,138 @@
+name: Database Migration
+
+on:
+  push:
+    paths:
+      - 'prisma/schema.prisma'
+      - 'prisma/migrations/**'
+    branches: [main, develop]
+  pull_request:
+    paths:
+      - 'prisma/schema.prisma'
+      - 'prisma/migrations/**'
+  workflow_dispatch:
+    inputs:
+      run_deploy:
+        description: 'Run deploy migration against staging DB'
+        type: boolean
+        default: false
+
+env:
+  NODE_VERSION: '22'
+
+jobs:
+  # ═══════════════════════════════════════════════════════════════
+  # 1. Validate schema + migration consistency
+  # ═══════════════════════════════════════════════════════════════
+
+  validate:
+    name: Validate Schema
+    runs-on: ubuntu-latest
+    timeout-minutes: 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: 'npm'
+      - run: npm ci
+      - run: npx prisma generate
+        env:
+          DATABASE_URL: ${{ secrets.MIGRATION_DATABASE_URL || 'mysql://placeholder:placeholder@localhost:3306/placeholder' }}
+
+      - name: Validate no schema drift
+        run: |
+          echo "Checking prisma schema is formatted..."
+          npx prisma format
+          if ! git diff --exit-code prisma/schema.prisma; then
+            echo "::error::prisma/schema.prisma has unformatted changes. Run 'npx prisma format' locally."
+            exit 1
+          fi
+
+      - name: Validate prisma generate output
+        run: |
+          if [ ! -f node_modules/.prisma/client/index.js ]; then
+            echo "::error::Prisma Client not generated"
+            exit 1
+          fi
+
+  # ═══════════════════════════════════════════════════════════════
+  # 2. Dry-run migration (check what would be applied)
+  # ═══════════════════════════════════════════════════════════════
+
+  dry-run:
+    name: Dry-Run Migration
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    needs: validate
+    services:
+      mysql:
+        image: mysql:8.0
+        env:
+          MYSQL_ROOT_PASSWORD: testpass
+          MYSQL_DATABASE: zhixi_test
+        ports:
+          - 3306:3306
+        options: >-
+          --health-cmd "mysqladmin ping -h localhost"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: ${{ env.NODE_VERSION }}
+          cache: 'npm'
+      - run: npm ci
+      - run: npx prisma generate
+        env:
+          DATABASE_URL: mysql://root:testpass@127.0.0.1:3306/zhixi_test
+
+      - name: Push schema to temp DB
+        run: npx prisma db push --skip-generate --accept-data-loss
+        env:
+          DATABASE_URL: mysql://root:testpass@127.0.0.1:3306/zhixi_test
+
+      - name: Apply migrations
+        run: npx prisma migrate deploy
+        env:
+          DATABASE_URL: mysql://root:testpass@127.0.0.1:3306/zhixi_test
+
+      - name: Verify migration completed
+        run: npx prisma migrate status
+        env:
+          DATABASE_URL: mysql://root:testpass@127.0.0.1:3306/zhixi_test
+
+  # ═══════════════════════════════════════════════════════════════
+  # 3. Deploy migration (staging/production)
+  # ═══════════════════════════════════════════════════════════════
+
+  deploy-migration:
+    name: Deploy Migration
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    needs: dry-run
+    if: github.event_name == 'workflow_dispatch' && inputs.run_deploy
+    environment: staging
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Deploy migration via SSH
+        uses: appleboy/ssh-action@v1
+        with:
+          host: ${{ secrets.DEPLOY_HOST }}
+          username: ${{ secrets.DEPLOY_USER }}
+          key: ${{ secrets.DEPLOY_SSH_KEY }}
+          script: |
+            set -e
+            cd /opt/zhixi/api-server
+
+            echo "=== Migration status before ==="
+            docker compose exec -T api npx prisma migrate status
+
+            echo "=== Applying migrations ==="
+            docker compose exec -T api npx prisma migrate deploy
+
+            echo "=== Migration status after ==="
+            docker compose exec -T api npx prisma migrate status