Unpack arch fields into fetch_arch / load_preset returns

Returning the 12-field list as a single element gave Gradio N+1
outputs but only 2 returned values ("didn't return enough output
values"). Spread the list with * so each field maps to its own
component. Same fix for load_preset (12 arch fields + status).

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

app.py

@@ -73,23 +73,23 @@ def fetch_arch(repo_id: str, filename: str, hf_token: str):
         detected = None
     quant_update = gr.update(value=detected) if detected else gr.update()
     if not repo_id or not filename:
-        return _empty_arch_fields(), "Pick a GGUF file first.", quant_update
+        return (*_empty_arch_fields(), "Pick a GGUF file first.", quant_update)
     try:
         meta = parse_hf_range(
             repo_id.strip(), filename, token=hf_token or None
         )
     except Exception as e:  # noqa: BLE001
-        return _empty_arch_fields(), f"Error reading GGUF header: {e}", quant_update
+        return (*_empty_arch_fields(), f"Error reading GGUF header: {e}", quant_update)
     quant_note = f", quant {detected}" if detected else ""
     if not meta.n_layer:
         return (
-            _arch_to_fields(meta),
+            *_arch_to_fields(meta),
             "Parsed header but architecture fields look empty; "
             "edit them manually below.",
             quant_update,
         )
     return (
-        _arch_to_fields(meta),
+        *_arch_to_fields(meta),
         f"Fetched {meta.architecture or 'model'}: "
         f"{meta.n_layer} layers, {meta.n_embd} embd, "
         f"{meta.n_head}/{meta.n_head_kv} heads, ctx {meta.training_ctx}, "
@@ -137,8 +137,8 @@ def _fields_to_arch(fields) -> ModelArch:
 
 def load_preset(name: str):
     if name and name in PRESETS:
-        return _arch_to_fields(PRESETS[name]), f"Loaded preset: {name}"
-    return _empty_arch_fields(), ""
+        return (*_arch_to_fields(PRESETS[name]), f"Loaded preset: {name}")
+    return (*_empty_arch_fields(), "")
 
 
 def _parse_gpu_list(text: str) -> list[float]: