fix: replace example chip gr.HTML+onclick with gr.Button for reliable input fill

gr.HTML inline onclick cannot update Gradio 6 Svelte component state.
Replace _example_chips_html() with gr.Button per chip wired to msg_box
via Gradio event system. CSS updated from .example-chip to .example-chip-btn.

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

app.py

@@ -318,13 +318,6 @@ _EXAMPLE_QUESTIONS = [
 ]
 
 
-def _example_chips_html() -> str:
-    """D4-4: 예시 질문 chip 카드"""
-    chips = "".join(
-        f'<button class="example-chip" onclick="fillInput({repr(q)})">{_html.escape(q)}</button>'
-        for q in _EXAMPLE_QUESTIONS
-    )
-    return f'<div id="example-chips" class="example-chips-wrap">{chips}</div>'
 
 
 # ── JavaScript (D3 + D4) ──────────────────────────────────────────
@@ -364,14 +357,10 @@ _JS = """
         if (el) el.classList.add('nav-active');
     };
 
-    // D4-3/4: 예시 질문 chip 클릭 → 입력창 채우기
-    window.fillInput = function(text) {
+    // D4-3: 입력창 포커스 유틸
+    window.focusInput = function() {
         const ta = document.querySelector('.pill-input textarea');
-        if (!ta) return;
-        const setter = Object.getOwnPropertyDescriptor(window.HTMLTextAreaElement.prototype, 'value').set;
-        setter.call(ta, text);
-        ta.dispatchEvent(new Event('input', { bubbles: true }));
-        ta.focus();
+        if (ta) ta.focus();
     };
 
     // D4-5: 설정 패널 토글
@@ -575,22 +564,23 @@ footer { display: none !important; }
 }
 
 /* ── 예시 질문 Chip (D4-4) ── */
-.example-chips-wrap { display: flex; flex-wrap: wrap; gap: 8px; padding: 8px 0 4px; }
-.example-chip {
-    background: #fff;
-    border: 1.5px solid #e2e8f0;
-    border-radius: 20px;
-    padding: 8px 16px;
-    font-size: .875rem;
-    color: #374151;
-    cursor: pointer;
-    transition: all .15s;
-    white-space: nowrap;
+.example-chips-row { padding: 6px 0 4px !important; flex-wrap: wrap !important; gap: 8px !important; }
+.example-chip-btn button {
+    border-radius: 20px !important;
+    border: 1.5px solid #e2e8f0 !important;
+    background: #fff !important;
+    color: #374151 !important;
+    padding: 8px 18px !important;
+    font-size: .875rem !important;
+    box-shadow: none !important;
+    white-space: nowrap !important;
+    transition: all .15s !important;
+    font-weight: 400 !important;
 }
-.example-chip:hover {
-    background: #eff6ff;
-    border-color: #93c5fd;
-    color: #1d4ed8;
+.example-chip-btn button:hover {
+    background: #eff6ff !important;
+    border-color: #93c5fd !important;
+    color: #1d4ed8 !important;
 }
 
 /* ── 컨트롤 패널 (D4-5) ── */
@@ -655,8 +645,8 @@ footer { display: none !important; }
 .dark .message-wrap .bot  { background: #1e293b !important; border-color: #334155 !important; }
 .dark .nav-btn button:hover { background: #1e293b !important; }
 .dark .nav-btn button.nav-active { background: #1e3a5f !important; color: #93c5fd !important; }
-.dark .example-chip { background: #1e293b !important; border-color: #334155 !important; color: #cbd5e1 !important; }
-.dark .example-chip:hover { background: #1e3a5f !important; border-color: #3b82f6 !important; }
+.dark .example-chip-btn button { background: #1e293b !important; border-color: #334155 !important; color: #cbd5e1 !important; }
+.dark .example-chip-btn button:hover { background: #1e3a5f !important; border-color: #3b82f6 !important; }
 .dark #control-panel { background: #1e293b !important; border-color: #334155 !important; }
 """
 
@@ -756,8 +746,12 @@ with gr.Blocks(title="율봇", css=_CUSTOM_CSS, theme=_THEME, js=_JS) as demo:
                     )
                     send_btn = gr.Button("↑", variant="primary", scale=0, min_width=48, elem_classes=["pill-send-btn"])
 
-                # D4-4: 예시 질문 Chips
-                gr.HTML(_example_chips_html())
+                # D4-4: 예시 질문 Chips (gr.Button — Gradio 이벤트로 msg_box 직접 업데이트)
+                with gr.Row(elem_classes=["example-chips-row"]):
+                    chip_btns = [
+                        gr.Button(q, elem_classes=["example-chip-btn"], size="sm")
+                        for q in _EXAMPLE_QUESTIONS
+                    ]
 
                 # 첨부 Accordions
                 with gr.Accordion("📷 이미지 첨부 (선택)", open=False):
@@ -816,6 +810,10 @@ with gr.Blocks(title="율봇", css=_CUSTOM_CSS, theme=_THEME, js=_JS) as demo:
 
     # ── 이벤트 바인딩 ─────────────────────────────────────────────
 
+    # 예시 질문 chips → msg_box 채우기
+    for _q, _btn in zip(_EXAMPLE_QUESTIONS, chip_btns):
+        _btn.click(fn=lambda x=_q: x, outputs=[msg_box])
+
     # 사이드바 네비게이션
     _panels = [panel_chat, panel_doc_register, panel_doc_manage]
     chat_nav_btn.click(show_chat_panel, outputs=_panels,