Add CI workflow for API service with linting and Docker build

This workflow includes linting, formatting, and building the API service Docker image.

Author: Santhosh-p653

.github/workflows/ci-api.yml

@@ -0,0 +1,104 @@
+
+name: CI — API Service
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+env:
+  REGISTRY: ghcr.io
+  IMAGE_NAME: ${{ github.repository }}/api
+
+jobs:
+  lint:
+    name: Lint & Import Check (API)
+    runs-on: ubuntu-latest
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          ref: ${{ github.head_ref || github.ref_name }}
+          fetch-depth: 0
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: "pip"
+
+      - name: Install lint dependencies
+        run: |
+          pip install flake8 black isort
+          [ -f api/requirements.txt ] && pip install -r api/requirements.txt || true
+
+      - name: Black auto-format
+        run: black api/
+
+      - name: isort auto-fix import order
+        run: isort api/
+
+      - name: Commit formatting fixes (if any)
+        uses: stefanzweifel/git-auto-commit-action@v5
+        with:
+          commit_message: "style: auto-format api/ with black & isort [skip ci]"
+          file_pattern: "api/**/*.py"
+
+      - name: Flake8 lint
+        run: flake8 api/ --max-line-length=100 --ignore=E203,W503
+
+      - name: Python import check (catch broken imports)
+        run: |
+          cd api
+          python -c "import ast, sys, pathlib
+          errors = []
+          for f in pathlib.Path('.').rglob('*.py'):
+              try:
+                  ast.parse(f.read_text())
+              except SyntaxError as e:
+                  errors.append(f'{f}: {e}')
+          if errors:
+              print('\n'.join(errors)); sys.exit(1)
+          print('All Python files parsed OK')"
+
+  build-and-push:
+    name: Build & Push API Image
+    runs-on: ubuntu-latest
+    needs: lint
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Log in to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          tags: |
+            type=sha,prefix=sha-
+            type=raw,value=latest,enable={{is_default_branch}}
+
+      - name: Build and push API Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: Dockerfile.api
+          push: ${{ github.ref == 'refs/heads/main' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max