refactor: 统一 DB/Redis 配置为 DSN 模式 + 移除 Helm/K8s 部署

- DatabaseConfig: Host/Port/User/Password/Name/DBName/SSLMode → 单个 DSN 字段
- RedisConfig: Host/Port/Password/DB/URL → 单个 DSN 字段
- 环境变量: GOCHAT_DATABASE_* (7个) → GOCHAT_DATABASE_DSN, GOCHAT_REDIS_* (5个) → GOCHAT_REDIS_DSN
- validator.go: DSN URL 解析校验 (scheme + host)
- redis.go: redis.ParseURL(cfg.DSN) 直连
- 所有 docker-compose / CI / shell 脚本 / .env 同步更新
- 删除 deploy/helm/ 整个目录 (20个文件)
- CI 删除 helm-validate / deploy-staging / deploy-production 三个 job
- 文档同步更新 (README, 架构设计, PRD, 滚动升级)

.github/workflows/ci.yml

@@ -68,13 +68,8 @@ jobs:
         env:
           GOCHAT_ENV: test
           GOCHAT_TEST_DB: ${{ matrix.db-mode }}
-          POSTGRES_HOST: localhost
-          POSTGRES_PORT: 5432
-          POSTGRES_USER: postgres
-          POSTGRES_PASSWORD: postgres
-          POSTGRES_DB: gochat_test
-          REDIS_HOST: localhost
-          REDIS_PORT: 6379
+          GOCHAT_DATABASE_DSN: postgres://postgres:postgres@localhost:5432/gochat_test?sslmode=disable
+          GOCHAT_REDIS_DSN: redis://localhost:6379
           GOPROXY: https://goproxy.cn,direct
         run: go test -v -race -coverprofile=coverage.out -timeout 180s ./internal/... ./pkg/... ./cmd/...
 
@@ -84,13 +79,8 @@ jobs:
         working-directory: backend
         env:
           GOCHAT_ENV: test
-          POSTGRES_HOST: localhost
-          POSTGRES_PORT: 5432
-          POSTGRES_USER: postgres
-          POSTGRES_PASSWORD: postgres
-          POSTGRES_DB: gochat_test
-          REDIS_HOST: localhost
-          REDIS_PORT: 6379
+          GOCHAT_DATABASE_DSN: postgres://postgres:postgres@localhost:5432/gochat_test?sslmode=disable
+          GOCHAT_REDIS_DSN: redis://localhost:6379
         run: go test -v -timeout 120s ./tests/e2e/...
 
       # Benchmark (quick sanity check, not full bench)
@@ -99,11 +89,7 @@ jobs:
         env:
           GOCHAT_ENV: test
           GOCHAT_TEST_DB: ${{ matrix.db-mode }}
-          POSTGRES_HOST: localhost
-          POSTGRES_PORT: 5432
-          POSTGRES_USER: postgres
-          POSTGRES_PASSWORD: postgres
-          POSTGRES_DB: gochat_test
+          GOCHAT_DATABASE_DSN: postgres://postgres:postgres@localhost:5432/gochat_test?sslmode=disable
         run: go test -bench=. -benchtime=1s -run=^$ -timeout 60s ./internal/service/... ./pkg/crypto/...
 
       # Coverage report
@@ -210,92 +196,4 @@ jobs:
           image-ref: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.sha }}
           format: 'table'
           exit-code: '1'
-          severity: 'CRITICAL,HIGH'
-
-  # ---- Stage 4: Validate Helm Chart ----
-  helm-validate:
-    name: Validate Helm Chart
-    needs: test
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Set up Helm
-        uses: azure/setup-helm@v3
-        with:
-          version: 'v3.14.0'
-
-      - name: Set up kubeval
-        run: |
-          curl -sfL https://github.com/yannh/kubeconform/releases/download/v0.6.4/kubeconform-linux-amd64.tar.gz | tar -xz
-          chmod +x kubeconform && mv kubeconform /usr/local/bin/
-
-      - name: Lint Helm chart
-        run: helm lint deploy/helm/gochat/
-
-      - name: Template and validate Helm chart
-        run: |
-          helm template gochat deploy/helm/gochat/ \
-            --values deploy/helm/gochat/values.yaml \
-            --values deploy/helm/gochat/values-production.yaml \
-            | kubeconform -summary -kubernetes-version 1.29.0
-
-  # ---- Stage 5: Deploy to Staging ----
-  deploy-staging:
-    name: Deploy to Staging
-    needs: [build, helm-validate]
-    runs-on: ubuntu-latest
-    if: github.ref == 'refs/heads/develop'
-    environment: staging
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Deploy to staging
-        uses: stefanprodan/helm-gh-action@v1.7.0
-        with:
-          context: ./deploy/helm/gochat
-          chart-ref: ./deploy/helm/gochat
-          cluster-config: staging-k8s-config
-          kube-config: ${{ secrets.KUBE_CONFIG_STAGING }}
-          namespace: gochat-staging
-          values: values.yaml
-          value-files: >-
-            values-staging.yaml
-          release-name: gochat-staging
-          atomic: true
-
-      # Post-deploy health check
-      - name: Health check
-        run: |
-          chmod +x backend/scripts/health_check.sh
-          GOCHAT_HOST=gochat-staging GOCHAT_PORT=3000 ./backend/scripts/health_check.sh --full --timeout 30
-
-  # ---- Stage 6: Deploy to Production ----
-  deploy-production:
-    name: Deploy to Production
-    needs: [build, helm-validate]
-    runs-on: ubuntu-latest
-    if: startsWith(github.ref, 'refs/heads/release/')
-    environment: production
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: Deploy to production
-        uses: stefanprodan/helm-gh-action@v1.7.0
-        with:
-          context: ./deploy/helm/gochat
-          chart-ref: ./deploy/helm/gochat
-          cluster-config: production-k8s-config
-          kube-config: ${{ secrets.KUBE_CONFIG_PRODUCTION }}
-          namespace: gochat-production
-          values: values.yaml
-          value-files: >-
-            values-production.yaml
-          release-name: gochat-production
-          atomic: true
-
-      # Post-deploy health check
-      - name: Health check
-        run: |
-          chmod +x backend/scripts/health_check.sh
-          GOCHAT_HOST=gochat-production GOCHAT_PORT=3000 ./backend/scripts/health_check.sh --full --timeout 30
+          severity: 'CRITICAL,HIGH'