feat: 新增 target description 字段，收紧 id/name 长度，调整延迟列和名称列

tests/server/checker/runner/cmd/runner.test.ts

@@ -30,6 +30,7 @@ function makeTarget(
       maxOutputBytes: 1024 * 1024,
       ...cmd,
     },
+    description: null,
     group: "default",
     id: "test-cmd",
     intervalMs: 60000,

tests/server/checker/runner/db/execute.test.ts

@@ -19,6 +19,7 @@ function makeTarget(db: Partial<ResolvedDbTarget["db"]>, overrides?: Partial<Res
       url: "sqlite://:memory:",
       ...db,
     },
+    description: null,
     group: "default",
     id: "test-db",
     intervalMs: 60000,

tests/server/checker/runner/http/runner.test.ts

@@ -155,6 +155,7 @@ describe("HttpChecker", () => {
     url?: string;
   }): ResolvedHttpTarget {
     return {
+      description: null,
       expect: overrides.expect,
       group: "default",
       http: {