feat(asl): Add Deep Research V2.0 development plan and Unifuncs API site coverage testing

Completed:
- Unifuncs DeepSearch API site coverage test (18 medical sites, 9 tier-1 available)
- ClinicalTrials.gov dedicated test (4 strategies, English query + depth>=10 works best)
- Deep Research V2.0 development plan (5-day phased delivery)
- DeepResearch engine capability guide (docs/02-common-capability/)
- Test scripts: test-unifuncs-site-coverage.ts, test-unifuncs-clinicaltrials.ts

Key findings:
- Tier-1 sites: PubMed(28), ClinicalTrials(38), NCBI(18), Scholar(10), Cochrane(4), CNKI(7), SinoMed(9), GeenMedical(5), VIP(1)
- Paid databases (WoS/Embase/Scopus/Ovid) cannot be accessed (no credential support)
- ClinicalTrials.gov requires English queries with max_depth>=10

Updated: ASL module status doc, system status doc, common capability list
Co-authored-by: Cursor <cursoragent@cursor.com>

docs/02-通用能力层/00-通用能力层清单.md

@@ -38,6 +38,7 @@
 | **认证授权** | `common/auth/` | ✅ | JWT认证 + 权限控制 |
 | **Prompt管理** | `common/prompt/` | ✅ | 动态Prompt配置 |
 | **🆕R统计引擎** | `r-statistics-service/` | ✅ | Docker化R统计服务（plumber） |
+| **🆕DeepResearch引擎** | `common/deepsearch/` | ✅ | Unifuncs DeepSearch API封装（9站点验证） |
 
 ### 前端通用能力