UI/UX D0: fix Textbox label, hide audio accordion, hide footer, hide ingest result box

- app.py: show_label=False on msg_box to remove "Textbox" label
- app.py: wrap audio input in gr.Accordion(open=False) to hide microphone error on load
- app.py: add CSS to hide Gradio footer branding
- app.py: ingest_status starts visible=False; ingest_files returns gr.update(visible=True)
- ROADMAP.md: add UI/UX design improvement section (D0–D3) and mark D0 complete

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -168,7 +168,7 @@ async def reset_chat(user_id):
 
 async def ingest_files(files):
     if not files:
-        return "파일을 선택해주세요."
+        return gr.update(value="파일을 선택해주세요.", visible=True)
     paths = [f if isinstance(f, str) else f.name for f in files]
     results = []
     for path in paths:
@@ -178,7 +178,7 @@ async def ingest_files(files):
             results.append(f"{name} → {result.get('chunks', '?')}개 청크")
         except Exception as e:
             results.append(f"{os.path.basename(path)} 오류: {e}")
-    return "\n".join(results)
+    return gr.update(value="\n".join(results), visible=True)
 
 
 async def list_docs():
@@ -262,7 +262,11 @@ def _sources_html(sources: list) -> str:
     )
 
 
-with gr.Blocks(title="율봇") as demo:
+_CUSTOM_CSS = """
+footer { display: none !important; }
+"""
+
+with gr.Blocks(title="율봇", css=_CUSTOM_CSS) as demo:
     gr.Markdown("# 율봇\n육아·금융 전문 AI 상담 도우미")
 
     user_state = gr.State(DEFAULT_USER)
@@ -283,7 +287,7 @@ with gr.Blocks(title="율봇") as demo:
         with gr.Row():
             msg_box = gr.Textbox(
                 placeholder="질문을 입력하세요... (Enter로 전송)",
-                label="",
+                show_label=False,
                 scale=5,
                 autofocus=True,
             )
@@ -298,14 +302,15 @@ with gr.Blocks(title="율봇") as demo:
             )
             gr.HTML("<div></div>", visible=False)  # spacer
 
-        with gr.Row():
-            audio_input = gr.Audio(
-                sources=["microphone"],
-                type="filepath",
-                label="음성으로 질문하기",
-                scale=4,
-            )
-            transcribe_btn = gr.Button("음성 → 텍스트 변환", scale=1)
+        with gr.Accordion("🎤 음성으로 질문하기", open=False):
+            with gr.Row():
+                audio_input = gr.Audio(
+                    sources=["microphone"],
+                    type="filepath",
+                    show_label=False,
+                    scale=4,
+                )
+                transcribe_btn = gr.Button("음성 → 텍스트 변환", scale=1)
 
         with gr.Row():
             show_thinking = gr.Checkbox(label="사고 과정 표시", value=True)
@@ -346,7 +351,7 @@ with gr.Blocks(title="율봇") as demo:
             label="파일 선택",
         )
         ingest_btn = gr.Button("문서 수집", variant="primary")
-        ingest_status = gr.Textbox(label="결과", interactive=False)
+        ingest_status = gr.Textbox(label="결과", interactive=False, visible=False)
         ingest_btn.click(ingest_files, inputs=[file_input], outputs=[ingest_status])
 
     with gr.Tab("문서 관리"):