Make --model optional when --audio-model or --image-model are specified

- --model is now optional if using audio or image models only
- Shows helpful error message with examples if no model specified
- Prints available models at startup

coderai

@@ -2999,7 +2999,7 @@ def parse_args():
         "--model",
         type=str,
         default=None,
-        help="Model name or path. For NVIDIA: HuggingFace model. For Vulkan: GGUF file path or HF repo",
+        help="Model name, path, or URL for text-to-text LLM. Optional if only using --audio-model or --image-model",
     )
     parser.add_argument(
         "--backend",
@@ -3186,8 +3186,10 @@ def main():
     
     # Get model name from args or prompt interactively
     model_name = args.model
-    if model_name is None:
-        print("No model specified. Please enter a model name.")
+    
+    # Validate: must have at least one model specified
+    if model_name is None and args.audio_model is None and args.image_model is None:
+        print("Error: At least one of --model, --audio-model, or --image-model must be specified.")
         print("")
         print("For NVIDIA backend (HuggingFace models):")
         print("  - microsoft/DialoGPT-medium")
@@ -3197,11 +3199,13 @@ def main():
         print("For Vulkan backend (GGUF models):")
         print("  - Local path: ./phi-3-mini-4k-instruct-q4_k_m.gguf")
         print("  - HuggingFace: microsoft/Phi-3-mini-4k-instruct-gguf")
+        print("  - URL: https://huggingface.co/.../model.gguf")
         print("")
-        model_name = input("Enter model name: ").strip()
-        
-        if not model_name:
-            print("Error: Model name is required")
+        print("For audio transcription:")
+        print("  - --audio-model base")
+        print("")
+        print("For image generation:")
+        print("  - --image-model stabilityai/stable-diffusion-xl-base-1.0")
         sys.exit(1)
     
     # Detect available backends
@@ -3212,7 +3216,8 @@ def main():
         print(f"  [{status}] {name}")
     print("")
     
-    # Load the main model
+    # Load the main model (only if specified)
+    if model_name:
         load_kwargs = {
             'offload_dir': args.offload_dir,
             'load_in_4bit': args.load_in_4bit,
@@ -3236,6 +3241,7 @@ def main():
             # Register with multi_model_manager
             multi_model_manager.set_default_model(model_name, load_kwargs)
             multi_model_manager.add_model(model_name, model_manager)
+            print(f"\nMain text model loaded: {model_name}")
         except Exception as e:
             print(f"\nError loading model: {e}")
             error_str = str(e).lower()
@@ -3258,6 +3264,8 @@ def main():
                     print("\n  Example Vulkan command:")
                     print(f"    coderai --backend vulkan --model {model_name}")
             sys.exit(1)
+    else:
+        print("\nNo main text model specified (--model). Running with audio/image models only.")
     
     # Set up audio model if specified
     if args.audio_model:
@@ -3291,6 +3299,7 @@ def main():
     import uvicorn
     print(f"\nStarting server on http://{args.host}:{args.port}")
     print(f"API documentation available at http://{args.host}:{args.port}/docs")
+    if model_manager.backend is not None:
         print(f"Using backend: {model_manager.backend_type}")
     
     # Print available models