Add UmbraAudio Voice Studio branding to web demo (icon + favicon)

Embeds the UmbraAudio logo as a data URI in the Gradio header and wires
the repo logo as the browser favicon. Cosmetic only; no TTS behavior
changes.

qwen_tts/cli/demo.py

@@ -18,9 +18,11 @@ A gradio demo for Qwen3 TTS models.
 """
 
 import argparse
+import base64
 import os
 import tempfile
 from dataclasses import asdict
+from pathlib import Path
 from typing import Any, Dict, List, Optional, Tuple
 
 import gradio as gr
@@ -59,6 +61,31 @@ def _maybe(v):
     return v if v is not None else gr.update()
 
 
+def _find_icon() -> Optional[Path]:
+    candidates = [
+        Path(os.environ.get("UMBRA_AUDIO_ICON", "")) if os.environ.get("UMBRA_AUDIO_ICON") else None,
+        Path("/Volumes/1TB_APL_Storage/UmbraAudio/UmbraAudio_icon.png"),
+        Path(__file__).resolve().parents[2] / "assets" / "logo.png",
+        Path("/Volumes/1TB_APL_Storage/UmbraAudio/UmbraAudio_icon.jpeg"),
+    ]
+    for c in candidates:
+        if c is not None and c.is_file():
+            return c
+    return None
+
+
+def _icon_data_uri() -> Optional[str]:
+    icon = _find_icon()
+    if icon is None:
+        return None
+    try:
+        data = base64.b64encode(icon.read_bytes()).decode("ascii")
+        mime = "image/png" if icon.suffix.lower() == ".png" else "image/jpeg"
+        return f"data:{mime};base64,{data}"
+    except OSError:
+        return None
+
+
 def build_parser() -> argparse.ArgumentParser:
     parser = argparse.ArgumentParser(
         prog="qwen-tts-demo",
@@ -168,6 +195,18 @@ def build_parser() -> argparse.ArgumentParser:
     return parser
 
 
+def _find_favicon() -> Optional[Path]:
+    for name in ("UmbraAudio_icon.png", "logo.png"):
+        p = Path(__file__).resolve().parents[3] / name
+        if p.is_file():
+            return p
+        alt = Path("/Volumes/1TB_APL_Storage/UmbraAudio") / name
+        if alt.is_file():
+            return alt
+    icon = _find_icon()
+    return icon if icon is not None and icon.suffix.lower() in (".png", ".gif", ".ico") else None
+
+
 def _resolve_checkpoint(args: argparse.Namespace) -> str:
     ckpt = args.checkpoint or args.checkpoint_pos
     if not ckpt:
@@ -275,6 +314,23 @@ def build_demo(tts: Qwen3TTSModel, ckpt: str, gen_kwargs_default: Dict[str, Any]
     css = ".gradio-container {max-width: none !important;}"
 
     with gr.Blocks(theme=theme, css=css) as demo:
+        icon_uri = _icon_data_uri()
+        if icon_uri:
+            with gr.Row():
+                with gr.Column(scale=1, min_width=120):
+                    gr.HTML(
+                        f'<img src="{icon_uri}" alt="UmbraAudio" '
+                        'style="max-height:96px; display:block; margin:0 auto;">'
+                    )
+                with gr.Column(scale=4):
+                    gr.Markdown(
+                        f"""
+# UmbraAudio Voice Studio
+**Checkpoint:** `{ckpt}`  
+**Model Type:** `{model_kind}`  
+"""
+                    )
+        else:
             gr.Markdown(
                 f"""
 # Qwen3 TTS Demo
@@ -621,6 +677,9 @@ def main(argv=None) -> int:
         share=args.share,
         ssl_verify=True if args.ssl_verify else False,
     )
+    favicon = _find_favicon()
+    if favicon is not None:
+        launch_kwargs["favicon_path"] = str(favicon)
     if args.ssl_certfile is not None:
         launch_kwargs["ssl_certfile"] = args.ssl_certfile
     if args.ssl_keyfile is not None: