fix: ship hermit-update (and hermit-service) as 1.0.1

Install hermit-update / hermit-service from make install and bootstrap;
keep cst-agent-* as compat symlinks.

Co-authored-by: Cursor <cursoragent@cursor.com>

MIGRATION.md

@@ -43,11 +43,12 @@ git clone https://git.whcself.xyz/WHC/CST-agent.git   # 兼容；请改 origin
 | 旧 | 新 |
 |---|---|
 | `cst-agent` | `hermit`（安装时仍提供 `cst-agent` → `hermit` 软链） |
-| `cst-agent-update` | 仍可用；内部装的是 `hermit` |
+| `cst-agent-update` | → `hermit-update`（软链；议会助手 → `hermit-service`） |
 | Release `cst-agent-VERSION-linux-*.tar.gz` | `hermit-VERSION-linux-*.tar.gz`（过渡期可能双发） |
 
 ```bash
-hermit --version    # hermit 1.0.0
+hermit --version    # hermit 1.0.x
+hermit-update       # 升级；兼容名 cst-agent-update
 cst-agent --version # 同二进制（软链）
 ```