Display admin dashboard on root page

- Root "/" now shows admin dashboard instead of JSON
- Uses same template as /admin endpoint
- Auto-refresh every 10 seconds

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

api/routes.py

@@ -1,11 +1,12 @@
 """FastAPI route handlers."""
 
 from fastapi import APIRouter, Depends, HTTPException, Request, Response
+from fastapi.responses import HTMLResponse
 from loguru import logger
+from starlette.templating import Jinja2Templates
 
 from config.settings import Settings
 from core.anthropic import get_token_count
-from core.session_tracker import SessionTracker
 from providers.nvidia_nim import metrics as nvidia_nim_metrics
 from providers.registry import ProviderRegistry
 
@@ -18,6 +19,8 @@ from .services import ClaudeProxyService
 
 router = APIRouter()
 
+templates = Jinja2Templates(directory="templates")
+
 DISCOVERED_MODEL_CREATED_AT = "1970-01-01T00:00:00Z"
 
 
@@ -197,16 +200,14 @@ async def probe_count_tokens(_auth=Depends(require_api_key)):
     return _probe_response("POST, HEAD, OPTIONS")
 
 
-@router.get("/")
-async def root(
-    settings: Settings = Depends(get_settings), _auth=Depends(require_api_key)
-):
-    """Root endpoint."""
-    tracker = SessionTracker.get_instance()
-    return {
-        "status": "ok",
-        "active_sessions": len(tracker._sessions),
-    }
+@router.get("/", response_class=HTMLResponse)
+async def root(request: Request, _auth=Depends(require_api_key)):
+    """Root endpoint - displays admin dashboard."""
+    from .admin import _get_admin_data
+
+    data = _get_admin_data()
+
+    return templates.TemplateResponse("admin.html", {"request": request, **data})
 
 
 @router.api_route("/", methods=["HEAD", "OPTIONS"])