perf(infra): NAS CPU 중기 2건 + 1건 보류 (CHECK_POINT 🟡)

#6 insta-lab Chromium Browser Pool — Playwright/Chromium 인스턴스를
모듈 레벨에서 보관하고 매 슬레이트마다 reuse. 카드 10장 렌더의
launch 비용 (~3초/회)이 사라짐. startup/shutdown lifecycle hook 추가.
crashed/disconnected 시 lazy 재초기화.

#8 realestate-lab 수집 병렬화 — collect_all과 delete_old_completed가
서로 다른 데이터 영역이라 ThreadPoolExecutor(2)로 병렬. asyncio.gather
대신 thread executor를 쓴 이유는 BackgroundScheduler+동기 함수 환경
에서 자연스럽고 추가 의존성 없기 때문. 매칭은 일관성 유지로 순차.

#7 stock async — 보류. 재진단 결과 stock은 BackgroundScheduler 사용
중이라 main loop 블로킹 없음. fetch 4회는 network I/O wait가
대부분이라 to_thread도 의미 없음. 진짜 효과를 보려면 AsyncIOScheduler
전환 + aiohttp 병렬이라 큰 리팩토링. 박재오 판단 대기.

CHECK_POINT.md 갱신.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

insta-lab/app/card_renderer.py

@@ -30,6 +30,47 @@ def _render_semaphore() -> asyncio.Semaphore:
     return _RENDER_SEMAPHORE
 
 
+# Chromium 브라우저 풀 — 매 슬레이트마다 launch 하지 않고 1개를 살려둠.
+# (CHECK_POINT 중기-6) 카드 10장 렌더 시간 ~30% 단축 기대.
+_PLAYWRIGHT = None
+_BROWSER = None
+
+
+async def init_browser() -> None:
+    """앱 startup hook에서 1회 호출. 이미 살아있으면 no-op."""
+    global _PLAYWRIGHT, _BROWSER
+    if _BROWSER is not None and _BROWSER.is_connected():
+        return
+    _PLAYWRIGHT = await async_playwright().start()
+    _BROWSER = await _PLAYWRIGHT.chromium.launch()
+    logger.info("Chromium browser pool 초기화 완료")
+
+
+async def shutdown_browser() -> None:
+    """앱 shutdown hook에서 1회 호출."""
+    global _PLAYWRIGHT, _BROWSER
+    if _BROWSER is not None:
+        try:
+            await _BROWSER.close()
+        except Exception:
+            logger.exception("browser close 중 예외 (무시)")
+        _BROWSER = None
+    if _PLAYWRIGHT is not None:
+        try:
+            await _PLAYWRIGHT.stop()
+        except Exception:
+            logger.exception("playwright stop 중 예외 (무시)")
+        _PLAYWRIGHT = None
+
+
+async def _get_browser():
+    """현재 브라우저 핸들 반환. crashed/None이면 재초기화 후 반환."""
+    global _BROWSER
+    if _BROWSER is None or not _BROWSER.is_connected():
+        await init_browser()
+    return _BROWSER
+
+
 def _resolve_template_dir() -> str:
     """Prefer config CARD_TEMPLATE_DIR if it exists; else fall back to in-repo templates/."""
     if os.path.isdir(CARD_TEMPLATE_DIR):
@@ -97,29 +138,28 @@ async def _render_slate_locked(slate_id: int, template: str) -> List[str]:
     out_dir = _slate_dir(slate_id)
     paths: List[str] = []
 
-    async with async_playwright() as p:
-        browser = await p.chromium.launch()
-        try:
-            ctx = await browser.new_context(viewport={"width": 1080, "height": 1350})
-            page = await ctx.new_page()
-            for spec in pages:
-                html_str = tmpl.render(**spec)
-                with tempfile.NamedTemporaryFile("w", suffix=".html", delete=False, encoding="utf-8") as f:
-                    f.write(html_str)
-                    html_path = f.name
+    browser = await _get_browser()
+    ctx = await browser.new_context(viewport={"width": 1080, "height": 1350})
+    try:
+        page = await ctx.new_page()
+        for spec in pages:
+            html_str = tmpl.render(**spec)
+            with tempfile.NamedTemporaryFile("w", suffix=".html", delete=False, encoding="utf-8") as f:
+                f.write(html_str)
+                html_path = f.name
+            try:
+                await page.goto(f"file://{html_path}", wait_until="networkidle")
+                out_path = os.path.join(out_dir, f"{spec['page_no']:02d}.png")
+                await page.screenshot(path=out_path, full_page=False, omit_background=False)
+                with open(out_path, "rb") as fp:
+                    file_hash = hashlib.md5(fp.read()).hexdigest()
+                db.add_card_asset(slate_id, spec["page_no"], out_path, file_hash)
+                paths.append(out_path)
+            finally:
                 try:
-                    await page.goto(f"file://{html_path}", wait_until="networkidle")
-                    out_path = os.path.join(out_dir, f"{spec['page_no']:02d}.png")
-                    await page.screenshot(path=out_path, full_page=False, omit_background=False)
-                    with open(out_path, "rb") as fp:
-                        file_hash = hashlib.md5(fp.read()).hexdigest()
-                    db.add_card_asset(slate_id, spec["page_no"], out_path, file_hash)
-                    paths.append(out_path)
-                finally:
-                    try:
-                        os.unlink(html_path)
-                    except OSError:
-                        pass
-        finally:
-            await browser.close()
+                    os.unlink(html_path)
+                except OSError:
+                    pass
+    finally:
+        await ctx.close()
     return paths