Initial commit: DeltaGlider - 99.9% compression for S3 storage

DeltaGlider reduces storage costs by storing only binary deltas between
similar files. Achieves 99.9% compression for versioned artifacts.

Key features:
- Intelligent file type detection (delta for archives, direct for others)
- Drop-in S3 replacement with automatic compression
- SHA256 integrity verification on every operation
- Clean hexagonal architecture
- Full test coverage
- Production tested with 200K+ files

Case study: ReadOnlyREST reduced 4TB to 5GB (99.9% compression)

.github/workflows/ci.yml

@@ -0,0 +1,200 @@
+name: CI
+
+on:
+  push:
+    branches: [main, develop]
+    tags: ["v*"]
+  pull_request:
+    branches: [main]
+
+env:
+  UV_VERSION: "0.5.13"
+  PYTHON_VERSION: "3.12"
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install UV
+        run: |
+          curl -LsSf https://astral.sh/uv/${{ env.UV_VERSION }}/install.sh | sh
+          echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Install dependencies
+        run: |
+          uv pip install --system ruff
+
+      - name: Run ruff check
+        run: |
+          uv run ruff check src tests
+
+      - name: Run ruff format check
+        run: |
+          uv run ruff format --check src tests
+
+  typecheck:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install UV
+        run: |
+          curl -LsSf https://astral.sh/uv/${{ env.UV_VERSION }}/install.sh | sh
+          echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Install dependencies
+        run: |
+          uv pip install --system mypy boto3-stubs[s3] types-python-dateutil
+
+      - name: Run mypy
+        run: |
+          uv run mypy src tests
+
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install UV
+        run: |
+          curl -LsSf https://astral.sh/uv/${{ env.UV_VERSION }}/install.sh | sh
+          echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Install xdelta3
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y xdelta3
+
+      - name: Install dependencies
+        run: |
+          uv pip install --system -e ".[dev]"
+
+      - name: Run unit tests
+        run: |
+          uv run pytest tests/unit -v --tb=short
+
+      - name: Run integration tests
+        run: |
+          uv run pytest tests/integration -v --tb=short
+
+  docker-build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Build Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: false
+          tags: deltaglider:test
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
+
+      - name: Test Docker image
+        run: |
+          docker run --rm deltaglider:test --help
+
+  e2e-test:
+    runs-on: ubuntu-latest
+    services:
+      localstack:
+        image: localstack/localstack:latest
+        ports:
+          - 4566:4566
+        env:
+          SERVICES: s3
+          DEBUG: 0
+          DATA_DIR: /tmp/localstack/data
+        options: >-
+          --health-cmd "curl -f http://localhost:4566/_localstack/health"
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install UV
+        run: |
+          curl -LsSf https://astral.sh/uv/${{ env.UV_VERSION }}/install.sh | sh
+          echo "$HOME/.cargo/bin" >> $GITHUB_PATH
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: ${{ env.PYTHON_VERSION }}
+
+      - name: Install xdelta3
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y xdelta3
+
+      - name: Install dependencies
+        run: |
+          uv pip install --system -e ".[dev]"
+
+      - name: Run E2E tests
+        env:
+          AWS_ACCESS_KEY_ID: test
+          AWS_SECRET_ACCESS_KEY: test
+          AWS_DEFAULT_REGION: us-east-1
+          AWS_ENDPOINT_URL: http://localhost:4566
+        run: |
+          uv run pytest tests/e2e -v -m e2e --tb=short
+
+  docker-push:
+    needs: [lint, typecheck, test, docker-build, e2e-test]
+    runs-on: ubuntu-latest
+    if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/')
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      - name: Extract metadata
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: deltaglider/deltaglider
+          tags: |
+            type=ref,event=tag
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max