Add PDF document service with AI extraction and per-app settings

- New `features/doc-service` FastAPI microservice: PDF upload, async
  text extraction (pdfplumber), AI classification via Anthropic/Ollama/
  LM Studio, per-user categories, file download
- Alembic migration isolated with `alembic_version_doc_service` table
- Main backend: httpx proxy routers for /api/documents/* and
  /api/documents/categories/*, admin settings API at /api/settings/*
- Runtime config in /config/doc_service_config.json (shared Docker
  volume); api_key masking on reads; atomic write with os.replace()
- Frontend: DocumentsPage, DocumentAdminSettingsPage, updated AppsPage
  launcher hub, simplified Nav (removed Settings link), new routes
- docker-compose: doc-service service, doc_data + app_config volumes,
  removed internal:true from backend-net for outbound AI API calls
- Fix pre-commit hook: probe Docker socket path so git subprocess picks
  up Docker Desktop on macOS
- Fix security_check.py: use sys.executable for bandit so venv python
  is used instead of system python

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

features/doc-service/pyproject.toml

@@ -0,0 +1,35 @@
+[build-system]
+requires = ["setuptools>=45"]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "doc-service"
+version = "0.1.0"
+requires-python = ">=3.11"
+dependencies = [
+    "fastapi>=0.111",
+    "uvicorn[standard]>=0.29",
+    "sqlalchemy[asyncio]>=2.0",
+    "asyncpg>=0.29",
+    "alembic>=1.13",
+    "pydantic-settings>=2.2",
+    "anthropic>=0.28",
+    "openai>=1.0",
+    "pdfplumber>=0.11",
+    "aiofiles>=23.0",
+    "python-multipart>=0.0.9",
+]
+
+[project.optional-dependencies]
+dev = [
+    "pytest>=8",
+    "pytest-asyncio>=0.23",
+    "httpx>=0.27",
+    "ruff>=0.4",
+]
+
+[tool.pytest.ini_options]
+asyncio_mode = "auto"
+
+[tool.ruff]
+line-length = 100