feat: add binary file attachment and import tools for Outline LTM system (#1)

Implement 3 new MCP tools:
- attach_file_to_document(document_id, file_path)
- upload_image_to_document(image_path, document_id, alt_text)
- import_file_to_outline(file_path, collection_id, parent_document_id)

Security:
- Restrict file access to /tmp via _validate_file_path with realpath
- 50MB max file size enforced client-side
- Symlink traversal blocked

Technical:
- Extract shared _upload_attachment() helper
- Stream files to presigned URLs instead of loading into memory
- Add combined lifespan to close OutlineClient on shutdown
- Update CI workflow with modern action versions and PR triggers

Tests:
- Add 28 tests covering path validation, size limits, upload flow,
  error handling, symlink traversal, and multipart imports

.gitea/workflows/build.yaml

@@ -5,6 +5,10 @@ on:
     branches:
       - main
       - master
+  pull_request:
+    branches:
+      - main
+      - master
 
 jobs:
   build:
@@ -13,17 +17,32 @@ jobs:
       image: catthehacker/ubuntu:act-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install dependencies
+        run: |
+          pip install uv
+          uv sync --extra dev
+
+      - name: Run tests
+        run: uv run pytest tests/ -v
 
       - name: Login to Gitea Container Registry
-        uses: docker/login-action@v2
+        if: github.event_name == 'push'
+        uses: docker/login-action@v3
         with:
           registry: gitea.ext.ben.io
           username: ${{ gitea.actor }}
           password: ${{ secrets.CR_PAT }}
 
       - name: Build and Push
-        uses: docker/build-push-action@v4
+        if: github.event_name == 'push'
+        uses: docker/build-push-action@v5
         with:
           context: .
           push: true