v0.2.0: Fix List Jobs bug, TLS 1.3 enforcement, client_disconnect_timeout, RwLock contention

Bug fixes:
- Fix List Jobs connection reset: Add client_disconnect_timeout (5s) to prevent TLS write truncation
- Enforce TLS 1.3 only: Add with_protocol_versions(&[&TLS13]) to rustls ServerConfig
- Fix RwLock contention: Release read lock before sorting in list_jobs()
- Fix systemd service: Remove ProtectSystem=strict (blocks package management)
- Fix systemd service: Change Type=notify to Type=simple (fixes restart hangs)
- Fix systemd service: Add DEBIAN_FRONTEND=noninteractive
- Fix systemd service: Add ReadWritePaths for apt/dpkg paths

CI/CD:
- Add Ubuntu 22.04 build job to CI workflow

E2E Testing:
- Add comprehensive E2E test suite (test_e2e.py)
- Tests cover health, packages, patches, jobs, security, and reboot endpoints

Other:
- Bump version to 0.2.0
- Add lessons learned documentation

.gitea/workflows/ci.yml

@@ -128,6 +128,38 @@ jobs:
           chmod +x scripts/upload-release.sh
           ./scripts/upload-release.sh "$TAG_NAME" "$FILE"
 
+  build-deb-u2204:
+    name: Build Debian Package (Ubuntu 22.04)
+    needs: [fmt, clippy, test]
+    runs-on: ubuntu-22.04
+    steps:
+      - name: Checkout repository
+        run: |
+          curl -sfL -H "Authorization: token ${{ secrets.GITEATOKEN }}" "https://gitea-lxc.moon-dragon.us/echo/linux_patch_api/archive/${GITHUB_SHA}.tar.gz" -o repo.tar.gz
+          tar -xzf repo.tar.gz --strip-components=1
+          rm -f repo.tar.gz
+      - name: Install Rust
+        run: |
+          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y --default-toolchain stable --profile minimal
+          . "$HOME/.cargo/env"
+          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+      - name: Install build dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential debhelper pkg-config libsystemd-dev
+      - name: Build Debian package
+        run: |
+          sudo dpkg-buildpackage -us -uc -b -d
+      - name: Upload to Gitea Release
+        if: startsWith(github.ref, 'refs/tags/')
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEATOKEN }}
+        run: |
+          TAG_NAME=${GITHUB_REF#refs/tags/}
+          FILE=$(ls ../linux-patch-api_*.deb 2>/dev/null | head -1)
+          chmod +x scripts/upload-release.sh
+          ./scripts/upload-release.sh "${TAG_NAME}-u2204" "$FILE"
+
   build-rpm:
     name: Build RPM Package
     needs: [fmt, clippy, test]