feat(subscription): 청약 일정 캘린더 뷰 추가

공고 목록 탭에 📅 캘린더 토글 버튼 추가.
캘린더 모드: 월간 그리드, 접수 시작일 기준 도트 표시 (상태별 색상).
날짜 클릭 시 해당일 공고 목록 패널 표시, 항목 클릭 시 상세 뷰로 전환.

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

src/pages/subscription/Subscription.css

@@ -1571,3 +1571,86 @@ input.sub-toggle:checked + .sub-toggle__label { color: var(--accent-subscription
 .ns-pass-count strong {
     font-weight: 700;
 }
+
+/* === 캘린더 뷰 ========================================================= */
+.sub-calendar {
+    background: var(--bg-secondary);
+    border: 1px solid var(--line);
+    border-radius: var(--radius-md);
+    overflow: hidden;
+}
+.sub-calendar__header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 10px 14px;
+    border-bottom: 1px solid var(--line);
+    font-weight: 600;
+    font-size: 14px;
+    color: var(--text-bright);
+}
+.sub-calendar__weekdays {
+    display: grid;
+    grid-template-columns: repeat(7, 1fr);
+    background: var(--bg-tertiary);
+    border-bottom: 1px solid var(--line);
+}
+.sub-calendar__weekday {
+    text-align: center;
+    padding: 6px 0;
+    font-size: 10px;
+    color: var(--text-dim);
+    font-weight: 600;
+}
+.sub-calendar__grid {
+    display: grid;
+    grid-template-columns: repeat(7, 1fr);
+}
+.sub-calendar__day {
+    min-height: 58px;
+    padding: 5px 4px 4px;
+    border-right: 1px solid var(--line);
+    border-bottom: 1px solid var(--line);
+    display: flex;
+    flex-direction: column;
+    gap: 3px;
+    cursor: default;
+    transition: background 0.1s;
+}
+.sub-calendar__day:nth-child(7n) { border-right: none; }
+.sub-calendar__day.is-empty { background: var(--bg-tertiary); opacity: 0.35; }
+.sub-calendar__day.has-items { cursor: pointer; }
+.sub-calendar__day.has-items:hover { background: var(--surface-raised); }
+.sub-calendar__day.is-today .sub-calendar__day-num {
+    background: var(--accent-cyan, #00d4ff);
+    color: var(--bg-primary);
+    border-radius: 50%;
+}
+.sub-calendar__day-num {
+    font-size: 11px;
+    color: var(--text-muted);
+    width: 20px;
+    height: 20px;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    line-height: 1;
+    font-weight: 500;
+}
+.sub-calendar__dots {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 2px;
+    padding: 0 2px;
+}
+.sub-calendar__dot {
+    width: 6px;
+    height: 6px;
+    border-radius: 50%;
+    flex-shrink: 0;
+}
+.sub-calendar__more {
+    font-size: 9px;
+    color: var(--text-dim);
+    line-height: 1.5;
+}