Implement sidebar navigation and model management features. Refactor App component to utilize a Sidebar for tab navigation, integrating ProfileList, GenerationForm, HistoryTable, and ServerStatus components. Introduce ModelManagement and ModelProgress components for handling AI model downloads and status updates. Enhance CSS for sidebar styling and add progress tracking functionality in the backend for model downloads.

backend/models.py

@@ -111,5 +111,26 @@ class HealthResponse(BaseModel):
     """Response model for health check."""
     status: str
     model_loaded: bool
+    model_downloaded: Optional[bool] = None  # Whether model is cached/downloaded
+    model_size: Optional[str] = None  # Current model size if loaded
     gpu_available: bool
     vram_used_mb: Optional[float] = None
+
+
+class ModelStatus(BaseModel):
+    """Response model for model status."""
+    model_name: str
+    display_name: str
+    downloaded: bool
+    size_mb: Optional[float] = None
+    loaded: bool = False
+
+
+class ModelStatusListResponse(BaseModel):
+    """Response model for model status list."""
+    models: List[ModelStatus]
+
+
+class ModelDownloadRequest(BaseModel):
+    """Request model for triggering model download."""
+    model_name: str