feat(similarity): add document similarity detection with embeddings and cosine similarity

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

app/api/__init__.py

@@ -19,6 +19,7 @@ from app.api.queue import router as queue_router
 from app.api.saved_searches import router as saved_searches_router
 from app.api.search import router as search_router
 from app.api.settings import router as settings_router
+from app.api.similarity import router as similarity_router
 from app.api.url_upload import router as url_upload_router
 
 # Import all the individual routers
@@ -46,3 +47,4 @@ router.include_router(url_upload_router)
 router.include_router(search_router)
 router.include_router(queue_router)
 router.include_router(saved_searches_router)
+router.include_router(similarity_router)