fix: disambiguate duplicate agent frontmatter names

Two pairs shared the same `name` field, which breaks tool/agent
registries that key on display name (Claude Code, etc.):

- 威胁检测工程师: engineering vs security
- 招聘专家: hr vs specialized

Rename only the YAML `name` (body titles unchanged for readability):

| File | New name |
|---|---|
| engineering-threat-detection-engineer | 威胁检测工程师（工程侧） |
| security-threat-detection-engineer | 威胁检测工程师（安全运营） |
| hr-recruiter | 招聘专家（HR 全流程） |
| specialized/recruitment-specialist | 人才获取专家 |

Avoided 招聘运营专家 because support/support-recruitment-specialist.md
already uses that name.

engineering/engineering-threat-detection-engineer.md

@@ -1,5 +1,5 @@
 ---
-name: 威胁检测工程师
+name: 威胁检测工程师（工程侧）
 description: 专精于 SIEM 规则开发、MITRE ATT&CK 覆盖度映射、威胁狩猎、告警调优和检测即代码流水线的安全运营检测工程专家。
 emoji: 🛡️
 color: "#7b2d8e"
@@ -225,7 +225,7 @@ DeviceProcessEvents
 
 ```yaml
 # GitHub Actions：检测规则 CI/CD 流水线
-name: Detection Engineering Pipeline
+name: 威胁检测工程师（工程侧）
 
 on:
   pull_request:

hr/hr-recruiter.md

@@ -1,5 +1,5 @@
 ---
-name: 招聘专家
+name: 招聘专家（HR 全流程）
 description: 深耕中国人才市场的全流程招聘专家，精通 Boss 直聘、猎聘、拉勾等主流招聘渠道运营，擅长简历筛选、面试协调、人才管线管理、校招社招全链路操盘，帮助企业高效精准地完成人才获取与入职闭环。
 emoji: 🎯
 color: "#9B59B6"

security/security-threat-detection-engineer.md

@@ -1,5 +1,5 @@
 ---
-name: 威胁检测工程师
+name: 威胁检测工程师（安全运营）
 description: 资深检测工程师，专注于 SIEM 规则开发、MITRE ATT&CK 覆盖映射、威胁狩猎、告警调优，以及面向安全运营团队的 detection-as-code（检测即代码）流水线。
 color: "#7b2d8e"
 emoji: 🎯
@@ -213,7 +213,7 @@ Techniques actively used by threat actors in our industry with ZERO detection:
 ### Detection-as-Code CI/CD 流水线
 ```yaml
 # GitHub Actions: Detection Rule CI/CD Pipeline
-name: Detection Engineering Pipeline
+name: 威胁检测工程师（安全运营）
 
 on:
   pull_request:

specialized/recruitment-specialist.md

@@ -1,5 +1,5 @@
 ---
-name: 招聘专家
+name: 人才获取专家
 description: "招聘运营与人才获取专家，精通国内主流招聘平台、人才评估体系和劳动法合规，帮助企业高效吸引、筛选和留住优秀人才，打造有竞争力的雇主品牌。"
 emoji: 🎯
 color: blue