feat: add Paperless-ngx document storage integration

- Add /documents router with webhook, upload, search, health endpoints
- Create DocumentSyncService for indexing documents to vectors/graph
- Add PaperlessClient for REST API integration
- Configure dependency injection for Paperless client
- Add document models for webhook payloads and responses
- Event-driven architecture via Paperless workflow webhooks

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/core/dependencies.py

@@ -22,6 +22,7 @@ from src.clients.wikijs_client import WikiJSClient
 from src.clients.searxng_client import SearXNGClient
 from src.clients.ollama_client import OllamaClient
 from src.clients.content_extractor import ContentExtractor
+from src.clients.paperless_client import PaperlessClient
 
 logger = logging.getLogger(__name__)
 
@@ -155,6 +156,28 @@ def get_content_extractor() -> ContentExtractor:
     return extractor
 
 
+@lru_cache
+def get_paperless_client() -> PaperlessClient:
+    """
+    Get Paperless-ngx client singleton.
+
+    Returns:
+        Initialized Paperless-ngx REST API client
+
+    Note: Returns None-like client if paperless_token is not configured
+    """
+    settings = get_settings()
+    if not settings.paperless_token:
+        logger.warning("Paperless token not configured - document storage disabled")
+    client = PaperlessClient(
+        base_url=settings.paperless_url,
+        token=settings.paperless_token,
+        timeout=settings.paperless_timeout
+    )
+    logger.debug(f"Created Paperless client: {settings.paperless_url}")
+    return client
+
+
 # Type aliases for FastAPI endpoint dependencies
 # Usage: def my_endpoint(neo4j: Neo4jDep):
 Neo4jDep = Annotated[Neo4jClient, Depends(get_neo4j_client)]
@@ -164,6 +187,7 @@ SearXNGDep = Annotated[SearXNGClient, Depends(get_searxng_client)]
 OllamaDep = Annotated[OllamaClient, Depends(get_ollama_client)]
 RedisDep = Annotated[aioredis.Redis, Depends(get_redis_client)]
 ContentExtractorDep = Annotated[ContentExtractor, Depends(get_content_extractor)]
+PaperlessDep = Annotated[PaperlessClient, Depends(get_paperless_client)]
 
 
 # Lifecycle management functions
@@ -202,6 +226,21 @@ async def startup_clients():
         logger.error(f"✗ Ollama health check failed: {e}")
         pass
 
+    # Check Paperless availability
+    settings = get_settings()
+    if settings.paperless_token:
+        try:
+            paperless = get_paperless_client()
+            is_healthy = await paperless.health_check()
+            if is_healthy:
+                logger.info(f"✓ Paperless-ngx ready: {settings.paperless_url}")
+            else:
+                logger.warning("✗ Paperless-ngx not responding")
+        except Exception as e:
+            logger.error(f"✗ Paperless health check failed: {e}")
+    else:
+        logger.info("○ Paperless-ngx not configured (document storage disabled)")
+
     # Qdrant, Wiki.js, SearXNG are lazy-initialized
     logger.info("Service clients startup complete")
 
@@ -230,7 +269,8 @@ async def shutdown_clients():
     clients_to_close = [
         ("Wiki.js", get_wikijs_client()),
         ("SearXNG", get_searxng_client()),
-        ("Ollama", get_ollama_client())
+        ("Ollama", get_ollama_client()),
+        ("Paperless", get_paperless_client()),
     ]
 
     for name, client in clients_to_close:
@@ -312,6 +352,18 @@ async def check_service_health() -> dict:
         logger.error(f"Ollama health check failed: {e}")
         health["ollama"] = False
 
+    # Paperless-ngx
+    settings = get_settings()
+    if settings.paperless_token:
+        try:
+            paperless = get_paperless_client()
+            health["paperless"] = await paperless.health_check()
+        except Exception as e:
+            logger.error(f"Paperless health check failed: {e}")
+            health["paperless"] = False
+    else:
+        health["paperless"] = None  # Not configured
+
     return health