feat(search): redesign search panel with chip cloud filters

- Add filter section with group, resolution, subtitle, season categories
- Implement multi-select filters with smart disabling for incompatible options
- Display result variant tags as non-clickable colored pills
- Unify tag styling (pill shape, 12px font) across filters and results
- Add expand/collapse for filter categories and variant overflow
- Normalize tag values (resolution: FHD/HD/4K, subtitle: 简/繁/双语)
- Calculate poster height to match 4 rows of variant chips (168px)
- Add click-outside-to-close for modal

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

webui/src/i18n/en.json

@@ -395,7 +395,8 @@
       "season": "Season",
       "clear": "Clear",
       "results": "results",
-      "active": "Filtering"
+      "active": "Filtering",
+      "collapse": "Less"
     },
     "confirm": {
       "title": "Add Subscription",

webui/src/i18n/zh-CN.json

@@ -395,7 +395,8 @@
       "season": "季度",
       "clear": "清除筛选",
       "results": "个结果",
-      "active": "筛选中"
+      "active": "筛选中",
+      "collapse": "收起"
     },
     "confirm": {
       "title": "添加订阅",