chore: initial project setup with backend, frontend, and infrastructure

Add complete NexaPantry application structure including:
- Docker Compose configuration with PostgreSQL, Redis, FastAPI backend, worker, frontend and Caddy
- Environment configuration template with database, auth, and service settings
- GitHub Actions CI workflow for backend/frontend linting, testing, auditing and Docker builds
- AGPL-3.0 license and comprehensive README with setup, development, and security documentation
- Backend

.github/workflows/ci.yml

@@ -0,0 +1,62 @@
+name: CI
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  backend:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: "3.12"
+      - name: Install backend
+        run: |
+          cd backend
+          python -m pip install --upgrade pip
+          pip install ".[dev]"
+      - name: Lint
+        run: cd backend && ruff check app
+      - name: Test
+        run: cd backend && pytest
+      - name: Audit
+        run: cd backend && pip-audit
+      - name: Bandit
+        run: cd backend && bandit -q -r app -x app/tests
+
+  frontend:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: "22"
+          cache: npm
+          cache-dependency-path: frontend/package-lock.json
+      - name: Install frontend
+        run: cd frontend && npm ci
+      - name: Lint
+        run: cd frontend && npm run lint
+      - name: Typecheck
+        run: cd frontend && npm run typecheck
+      - name: Test
+        run: cd frontend && npm test -- --run
+      - name: Audit
+        run: cd frontend && npm audit --audit-level=moderate
+
+  docker:
+    runs-on: ubuntu-latest
+    needs: [backend, frontend]
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build images
+        run: docker compose build
+      - name: Trivy filesystem scan
+        uses: aquasecurity/trivy-action@master
+        with:
+          scan-type: fs
+          scan-ref: .
+          severity: CRITICAL,HIGH
+          exit-code: "0"