feat(cupang): 쿠팡 밀크런 모듈 추가 (출고 달력/박스계산/입고센터)

- app/modules/cupang: router/db/store/itemcode + 템플릿 5종
- cupang_db 전용(JSON 폴백 없음). CUPANG_DB_URL 미설정 시 안내 페이지
- 월간 달력 + 출고 묶음(헤더+라인), 박스 입수량 자동계산(서버 재계산)
- 입고센터 관리(사용중 soft delete), 박스규칙 upsert, 엑셀 내보내기
- 상품 검색은 itemcode_db 읽기 전용(미설정 시 수동 입력)
- MODULE_KEYS/메뉴/아이콘/라벨 동기화, scripts/sql/cupang_db_init.sql(멱등)
- app/data/ gitignore 추가(PII)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/modules/cupang/templates/cupang/index.html

@@ -0,0 +1,87 @@
+{% extends "erp_base.html" %}
+
+{% block head_extra %}<link rel="stylesheet" href="/static/cupang.css" />{% endblock %}
+
+{% block content %}
+<section class="cpg">
+
+  <!-- 페이지 액션 -->
+  <div class="erp-page-actions cpg-actions">
+    <a class="erp-btn erp-btn-primary" href="/cupang/new">+ 신규 등록</a>
+    <a class="erp-btn erp-btn-outline" href="/cupang/centers">입고센터 관리</a>
+    <a class="erp-btn erp-btn-outline" href="/cupang/box-rules">박스 입수량</a>
+    <a class="erp-btn erp-btn-outline" href="/cupang/export?year={{ year }}&month={{ month }}">엑셀({{ month }}월)</a>
+  </div>
+
+  <div class="cpg-layout">
+    <!-- ── 왼쪽: 큰 월간 달력 ── -->
+    <div class="erp-card cpg-cal-card">
+      <div class="cpg-cal-head">
+        <a class="erp-btn erp-btn-outline cpg-nav-btn"
+           href="/cupang/?year={{ prev_y }}&month={{ prev_m }}">‹</a>
+        <h2 class="cpg-cal-title">{{ year }}년 {{ month }}월</h2>
+        <a class="erp-btn erp-btn-outline cpg-nav-btn"
+           href="/cupang/?year={{ next_y }}&month={{ next_m }}">›</a>
+      </div>
+
+      <div class="cpg-cal-grid">
+        {% for wd in weekdays %}
+        <div class="cpg-cal-wd {% if loop.index0 == 0 %}cpg-sun{% elif loop.index0 == 6 %}cpg-sat{% endif %}">{{ wd }}</div>
+        {% endfor %}
+
+        {% for week in cal_weeks %}
+          {% for cell in week %}
+          <a class="cpg-cal-cell
+                    {% if not cell.in_month %}cpg-out{% endif %}
+                    {% if cell.is_today %}cpg-today{% endif %}
+                    {% if cell.is_selected %}cpg-selected{% endif %}"
+             href="/cupang/?year={{ year }}&month={{ month }}&date={{ cell.date }}">
+            <span class="cpg-cal-day">{{ cell.day }}</span>
+            <span class="cpg-cal-badges">
+              {% if cell.counts.document %}<span class="erp-badge erp-badge-neutral cpg-mini">작성 {{ cell.counts.document }}</span>{% endif %}
+              {% if cell.counts.ship %}<span class="erp-badge erp-badge-inverse cpg-mini">출고 {{ cell.counts.ship }}</span>{% endif %}
+              {% if cell.counts.arrival %}<span class="erp-badge erp-badge-success cpg-mini">입고 {{ cell.counts.arrival }}</span>{% endif %}
+            </span>
+          </a>
+          {% endfor %}
+        {% endfor %}
+      </div>
+    </div>
+
+    <!-- ── 오른쪽: 선택일 출고 묶음 리스트 ── -->
+    <div class="erp-card cpg-list-card">
+      <div class="cpg-list-head">
+        <h2>{{ selected_date }} 출고</h2>
+        <span class="erp-muted">{{ sel_shipments|length }}건</span>
+      </div>
+
+      {% if sel_shipments %}
+      <ul class="cpg-list">
+        {% for s in sel_shipments %}
+        <li class="cpg-list-item">
+          <a href="/cupang/{{ s.id }}" class="cpg-list-link">
+            <div class="cpg-list-top">
+              <strong>{{ s.center_name_snapshot or '센터 미지정' }}</strong>
+              {% set badge = 'erp-badge-neutral' %}
+              {% if s.status == '출고완료' %}{% set badge = 'erp-badge-inverse' %}
+              {% elif s.status == '센터입고완료' %}{% set badge = 'erp-badge-success' %}
+              {% elif s.status == '취소' %}{% set badge = 'erp-badge-danger' %}{% endif %}
+              <span class="erp-badge {{ badge }}">{{ s.status }}</span>
+            </div>
+            <div class="cpg-list-meta erp-muted">
+              출고 {{ s.ship_date }} · 입고 {{ s.center_arrival_date }} · {{ s.ship_method }}
+              {% if s.outbound_summary %}<br>{{ s.outbound_summary }}{% endif %}
+            </div>
+          </a>
+        </li>
+        {% endfor %}
+      </ul>
+      {% else %}
+      <p class="erp-muted cpg-empty">선택한 날짜의 출고 묶음이 없습니다.
+        <a href="/cupang/new">신규 등록</a></p>
+      {% endif %}
+    </div>
+  </div>
+
+</section>
+{% endblock %}