백테스팅 화면 상단 툴바에 빠른 실행 기능 추가

- 헤더 중앙에 종목·타임프레임·전략 드롭다운 + 실행 버튼 추가
- 실행 클릭 시 /api/candles/history에서 캔들 로드 → runBacktest 호출
- 완료 후 결과 목록 자동 갱신 및 백테스팅 탭 활성화
- 실행 중 스피너 표시, 오류 시 인라인 에러 메시지 표시
- btd-header-run·btd-run-select·btd-run-btn·btd-run-spinner CSS 추가

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/styles/backtestDashboard.css

@@ -838,6 +838,93 @@
   gap: 8px;
 }
 
+/* ── 빠른 백테스팅 실행 툴바 ────────────────────────────────────────────── */
+.btd-header-run {
+  display: flex;
+  align-items: center;
+  gap: 6px;
+  flex: 1;
+  justify-content: center;
+  min-width: 0;
+}
+
+.btd-run-select {
+  background: var(--se-bg-elevated, var(--bg2));
+  border: 1px solid var(--se-border);
+  color: var(--se-text);
+  border-radius: 7px;
+  padding: 5px 8px;
+  font-size: 0.76rem;
+  cursor: pointer;
+  height: 30px;
+  outline: none;
+  transition: border-color 0.15s;
+  min-width: 0;
+}
+.btd-run-select:focus {
+  border-color: var(--se-accent, #3d9be9);
+}
+.btd-run-select:disabled {
+  opacity: 0.45;
+  cursor: not-allowed;
+}
+.btd-run-select--strategy {
+  flex: 1;
+  max-width: 180px;
+}
+
+.btd-run-btn {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  width: 30px;
+  height: 30px;
+  border-radius: 50%;
+  border: 1px solid var(--se-accent, #3d9be9);
+  background: color-mix(in srgb, var(--se-accent, #3d9be9) 18%, transparent);
+  color: var(--se-accent, #3d9be9);
+  cursor: pointer;
+  transition: background 0.15s, border-color 0.15s, transform 0.1s;
+  flex-shrink: 0;
+}
+.btd-run-btn:hover:not(:disabled) {
+  background: color-mix(in srgb, var(--se-accent, #3d9be9) 32%, transparent);
+  transform: scale(1.08);
+}
+.btd-run-btn:active:not(:disabled) {
+  transform: scale(0.95);
+}
+.btd-run-btn:disabled {
+  opacity: 0.35;
+  cursor: not-allowed;
+}
+.btd-run-btn--loading {
+  border-color: var(--se-text-muted);
+  color: var(--se-text-muted);
+}
+
+.btd-run-spinner {
+  display: inline-block;
+  width: 12px;
+  height: 12px;
+  border: 2px solid currentColor;
+  border-top-color: transparent;
+  border-radius: 50%;
+  animation: btd-spin 0.7s linear infinite;
+}
+@keyframes btd-spin {
+  to { transform: rotate(360deg); }
+}
+
+.btd-run-error {
+  font-size: 0.71rem;
+  color: var(--se-sell, #f23645);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  max-width: 200px;
+}
+
 .btd-btn {
   border: 1px solid var(--se-border);
   background: var(--se-bg-elevated, var(--bg2));