fix: 下架后卡片变灰+按钮变灰，isActive存为boolean

根因: oils store 存 isActive = oil.is_active ?? true
  oil.is_active=0 时 0??true=0，但检查用 ===false，0!==false

修复: isActive = oil.is_active !== 0 (true/false boolean)

UI:
- 下架后弹窗不关闭，按钮变灰显示"✓ 已下架 · 点击重新上架"
- 卡片立即变灰(oil-chip--inactive class生效)
- 重新上架后恢复正常

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/stores/oils.js

@@ -68,7 +68,7 @@ export const useOilsStore = defineStore('oils', () => {
         bottlePrice: oil.bottle_price,
         dropCount: oil.drop_count,
         retailPrice: oil.retail_price ?? null,
-        isActive: oil.is_active ?? true,
+        isActive: oil.is_active !== 0,
         enName: oil.en_name ?? null,
       }
     }

frontend/src/views/OilReference.vue

@@ -330,9 +330,11 @@
 
           <div style="display:flex;gap:10px;justify-content:space-between;margin-top:16px">
             <button
-              style="padding:8px 14px;border-radius:8px;font-size:13px;cursor:pointer;font-family:inherit;border:1.5px solid #e8b4b0;background:transparent;color:#c0392b"
+              :style="getMeta(editingOilName)?.isActive === false
+                ? 'padding:8px 14px;border-radius:8px;font-size:13px;cursor:pointer;font-family:inherit;border:1.5px solid #ccc;background:#f0f0f0;color:#999'
+                : 'padding:8px 14px;border-radius:8px;font-size:13px;cursor:pointer;font-family:inherit;border:1.5px solid #e8b4b0;background:transparent;color:#c0392b'"
               @click="toggleOilActive"
-            >{{ getMeta(editingOilName)?.isActive === false ? '重新上架' : '下架' }}</button>
+            >{{ getMeta(editingOilName)?.isActive === false ? '✓ 已下架 · 点击重新上架' : '下架' }}</button>
             <div style="display:flex;gap:10px">
               <button class="btn-outline" @click="editingOilName = null">取消</button>
               <button class="btn-primary" @click="saveEditOil">保存</button>
@@ -702,7 +704,6 @@ async function toggleOilActive() {
     await oils.loadOils()
     cardVersion.value++
     ui.showToast(newActive ? '已重新上架' : '已下架')
-    editingOilName.value = null
   } catch (e) {
     ui.showToast('网络错误: ' + e.message)
   }