feat(skill): REQ-20260406-0004 技能三层分离重构（7主线+16插件）

批次1: req-prd 瘦身 + req-design 重定位 + dev-coding 聚焦
批次2: dev-review 新建 + review-checklist 插件
批次3: dev-integration 新建 + req-compare 拆出
批次4: 插件完善 (req-research/db-migration/dev-scaffold/deploy-rollback)
批次5: 平台拆分 (dev-ios/dev-android/dev-mcp/dev-pda) + dev 分组更新
批次6: marketplace.json 32→44 plugins

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

skills-req/req-research-plugin/.claude-plugin/plugin.json

@@ -0,0 +1,6 @@
+{
+  "name": "req-research-plugin",
+  "description": "需求调研插件。代码审计、数据库分析、现有功能调研。挂载在 analysis 阶段，需要深度调研时激活。",
+  "version": "1.0.0",
+  "author": { "name": "qiudl" }
+}