Add comprehensive OpenAPI documentation - Enhanced FastAPI app with detailed API docs and created comprehensive API guide

src/server/fastapi_app.py

@@ -229,11 +229,69 @@ async def lifespan(app: FastAPI):
 # Create FastAPI application
 app = FastAPI(
     title="AniWorld API",
-    description="FastAPI-based AniWorld server with simple master password authentication",
+    description="""
+    ## AniWorld Management System
+
+    A comprehensive FastAPI-based application for managing anime series and episodes.
+
+    ### Features
+
+    * **Series Management**: Search, track, and manage anime series
+    * **Episode Tracking**: Monitor missing episodes and download progress  
+    * **Authentication**: Secure master password authentication with JWT tokens
+    * **Real-time Updates**: WebSocket support for live progress tracking
+    * **File Management**: Automatic file scanning and organization
+    * **Download Queue**: Queue-based download management system
+
+    ### Authentication
+
+    Most endpoints require authentication using a master password.
+    Use the `/auth/login` endpoint to obtain a JWT token, then include it
+    in the `Authorization` header as `Bearer <token>`.
+
+    ### API Versioning
+
+    This API follows semantic versioning. Current version: **1.0.0**
+    """,
     version="1.0.0",
     docs_url="/docs",
     redoc_url="/redoc",
-    lifespan=lifespan
+    lifespan=lifespan,
+    contact={
+        "name": "AniWorld API Support",
+        "url": "https://github.com/your-repo/aniworld",
+        "email": "support@aniworld.com",
+    },
+    license_info={
+        "name": "MIT",
+        "url": "https://opensource.org/licenses/MIT",
+    },
+    tags_metadata=[
+        {
+            "name": "Authentication",
+            "description": "Operations related to user authentication and session management",
+        },
+        {
+            "name": "Anime",
+            "description": "Operations for searching and managing anime series",
+        },
+        {
+            "name": "Episodes", 
+            "description": "Operations for managing individual episodes",
+        },
+        {
+            "name": "Downloads",
+            "description": "Operations for managing the download queue and progress",
+        },
+        {
+            "name": "System",
+            "description": "System health, configuration, and maintenance operations",
+        },
+        {
+            "name": "Files",
+            "description": "File system operations and scanning functionality",
+        },
+    ]
 )
 
 # Configure templates