feat(scheduler): lifecycle 真实接线适配器(2/2) + 装配 BuildRealConfig

把 scheduler 的 stub lifecycle 换成 SQL 后端真实实现,并接入 server:
- SQLLifecycle：MySQL 后端,同时满足 detect.LifecycleService 与
  orchestrate.LifecycleService(两个 thin adapter 包装共享核心)。
  - TransitionStatus：乐观锁 UPDATE nodes SET status WHERE id AND status=from
    → rows affected(1=成功/0=冲突 no-op)+ 写 node_events(按状态映射 enum,
    eventForStatus 纯函数已单测)+ bump directory_version,全在一个事务内。
  - ListNodes/GetNode/SetWeight/BumpVersion/GetLoad(读 LoadCache)/WriteAuditLog。
  - 已知限制:无历史 load 表 → GetLoadHistory 返回当前点(掉量规则安全降级);
    destroy 的 cert 撤销留 TODO(provision 已拆 VM,撤销为纵深防御,待机群再接)。
- BuildRealConfig：用真实 lifecycle + provisionAdapter 装配三循环。
- main.go：SCHED_ENABLED 且有 DB 时走 BuildRealConfig(provision 无厂商凭证则
  CreateNode 优雅失败、替换保持 pending),否则回退 stub。
- 全量 server 23 包测试通过;e2e(判封→drain→换机→置备)待机群+厂商凭证验证。

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/internal/scheduler/wiring_lifecycle_test.go

@@ -0,0 +1,22 @@
+package scheduler
+
+import "testing"
+
+func TestEventForStatus(t *testing.T) {
+	cases := map[string]string{
+		"up":                "marked_up",
+		"draining":          "draining",
+		"blocked_suspect":   "blocked_suspect",
+		"blocked_confirmed": "blocked_confirmed",
+		"destroyed":         "destroyed",
+		"probing":           "provisioned",
+		"provisioning":      "provisioned",
+		"down":              "", // no event enum → skip writing an event row
+		"bogus":             "",
+	}
+	for status, want := range cases {
+		if got := eventForStatus(status); got != want {
+			t.Errorf("eventForStatus(%q) = %q, want %q", status, got, want)
+		}
+	}
+}