feat: AI 채팅 다듬기 — 저장소 컨텍스트·표시제목·마크다운 렌더·말투

- 컨텍스트에 저장소 목록 추가(RepoService.findAll), slug 빼고 표시 제목만 노출
- AI 응답 마크다운 렌더링: shared/utils/markdown.ts (escapeHtml 후 신뢰 태그만 조립, 의존성 0, XSS 안전 — 굵게/목록/코드/제목/링크)
- 시스템 프롬프트: 간결·이모지/사과 남발 금지·과도한 존칭 지양·마크다운 사용·저장소는 표시제목으로 안내

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/components/AgentChatPanel.vue

@@ -5,6 +5,7 @@ import { nextTick, ref, watch } from 'vue'
 import { storeToRefs } from 'pinia'
 import { useAiStore } from '@/stores/ai.store'
 import { relativeTimeKo } from '@/shared/utils/format'
+import { renderMarkdown } from '@/shared/utils/markdown'
 
 interface Props {
   open: boolean
@@ -235,7 +236,18 @@ async function removeConv(id: string) {
             v-if="m.role === 'assistant'"
             class="ac-ava"
           >AI</span>
-          <div class="ac-bubble">
+          <!-- AI 응답은 마크다운 렌더(renderMarkdown 가 escapeHtml 후 신뢰 태그만 조립 → XSS 안전) -->
+          <!-- eslint-disable vue/no-v-html -->
+          <div
+            v-if="m.role === 'assistant'"
+            class="ac-bubble ac-md"
+            v-html="renderMarkdown(m.content)"
+          />
+          <!-- eslint-enable vue/no-v-html -->
+          <div
+            v-else
+            class="ac-bubble"
+          >
             {{ m.content }}
           </div>
         </div>
@@ -465,6 +477,65 @@ async function removeConv(id: string) {
   background: #f4f5f7;
   border-top-left-radius: 0.25rem;
 }
+
+/* 마크다운 렌더 영역 — v-html 내부라 :deep() 로 타겟 */
+.ac-bubble.ac-md {
+  white-space: normal;
+}
+.ac-md :deep(p) {
+  margin: 0 0 0.5em;
+}
+.ac-md :deep(p:last-child) {
+  margin-bottom: 0;
+}
+.ac-md :deep(ul),
+.ac-md :deep(ol) {
+  margin: 0.25em 0 0.5em;
+  padding-left: 1.25em;
+}
+.ac-md :deep(li) {
+  margin: 0.15em 0;
+}
+.ac-md :deep(strong) {
+  font-weight: 700;
+}
+.ac-md :deep(code) {
+  background: rgba(0, 0, 0, 0.06);
+  padding: 0.05em 0.3em;
+  border-radius: 0.25rem;
+  font-size: 0.85em;
+  font-family: ui-monospace, 'SFMono-Regular', monospace;
+}
+.ac-md :deep(pre.md-pre) {
+  background: #1f2430;
+  color: #e6e8ec;
+  padding: 0.6rem 0.75rem;
+  border-radius: 0.5rem;
+  overflow-x: auto;
+  margin: 0.4em 0;
+}
+.ac-md :deep(pre.md-pre code) {
+  background: none;
+  padding: 0;
+  color: inherit;
+  font-size: 0.8125rem;
+}
+.ac-md :deep(.md-h) {
+  font-weight: 700;
+  margin: 0.4em 0 0.25em;
+}
+.ac-md :deep(.md-h1) {
+  font-size: 1.05em;
+}
+.ac-md :deep(hr) {
+  border: none;
+  border-top: 1px solid var(--border-strong);
+  margin: 0.6em 0;
+}
+.ac-md :deep(a) {
+  color: var(--accent);
+  text-decoration: underline;
+}
 .ac-msg.user .ac-bubble {
   background: var(--accent);
   color: #fff;