Update HTML templates and JavaScript for FastAPI compatibility

- Replace Flask url_for() with direct /static/ paths in all HTML templates
- Update CSS and JavaScript file references to use FastAPI static mount
- Convert Flask-specific template patterns to FastAPI-compatible syntax
- Update JavaScript API endpoints to match new FastAPI route structure:
  * /api/series -> /api/v1/anime
  * /api/search -> /api/v1/anime/search
  * /api/rescan -> /api/v1/anime/rescan
- Add web interface routes for serving HTML templates
- Add template response endpoints for /app, /login, /setup, /queue
- Mark HTML template and JavaScript migration tasks as completed
- Maintain Jinja2 template compatibility with FastAPI

src/server/fastapi_app.py

@@ -26,7 +26,7 @@ sys.path.insert(0, os.path.abspath(parent_dir))
 from fastapi import FastAPI, HTTPException, Depends, Security, status, Request
 from fastapi.security import HTTPBearer, HTTPAuthorizationCredentials
 from fastapi.middleware.cors import CORSMiddleware
-from fastapi.responses import JSONResponse
+from fastapi.responses import JSONResponse, HTMLResponse
 from fastapi.staticfiles import StaticFiles
 from fastapi.templating import Jinja2Templates
 from pydantic import BaseModel, Field
@@ -375,6 +375,27 @@ async def root():
     """Root endpoint redirect to docs."""
     return {"message": "AniWorld API", "documentation": "/docs", "health": "/health"}
 
+# Web interface routes
+@app.get("/app", response_class=HTMLResponse)
+async def web_app(request: Request):
+    """Serve the main web application."""
+    return templates.TemplateResponse("base/index.html", {"request": request})
+
+@app.get("/login", response_class=HTMLResponse)  
+async def login_page(request: Request):
+    """Serve the login page."""
+    return templates.TemplateResponse("base/login.html", {"request": request})
+
+@app.get("/setup", response_class=HTMLResponse)
+async def setup_page(request: Request):
+    """Serve the setup page."""
+    return templates.TemplateResponse("base/setup.html", {"request": request})
+
+@app.get("/queue", response_class=HTMLResponse)
+async def queue_page(request: Request):
+    """Serve the queue page."""
+    return templates.TemplateResponse("base/queue.html", {"request": request})
+
 # Anime endpoints (protected)
 @app.get("/api/anime/search", response_model=List[AnimeResponse], tags=["Anime"])
 async def search_anime(