feat: 扩展配置变量替换范围至 server/probes/targets，支持空默认值语法

tests/server/checker/variables.test.ts

@@ -150,36 +150,63 @@ describe("config variables", () => {
     }
   });
 
-  test("替换范围仅 targets，且跳过 id 和 type 字段", () => {
+  test("替换范围覆盖 server、probes、targets，并跳过 variables 和 target 顶层 id/type", () => {
     const result = resolveVariables({
       defaults: { interval: "${interval}" },
-      server: { host: "${host}" },
+      probes: { execution: { maxConcurrentChecks: "${maxConcurrentChecks}" } },
+      server: { host: "${host}", logging: { level: "${logLevel}" }, storage: { retention: "${retention}" } },
       targets: [
         {
           cmd: {
             args: ["--host", "${host}"],
-            env: { TOKEN: "${token}" },
+            env: { "${TOKEN_KEY}": "${token}" },
             exec: "echo",
           },
+          expect: { rows: [{ id: { equals: "${expectedId}" }, type: { equals: "${expectedType}" } }] },
           id: "${id}",
           type: "${type}",
         },
       ],
-      variables: { host: "localhost", id: "resolved", interval: "30s", token: "abc", type: "cmd" },
+      variables: {
+        expectedId: 1,
+        expectedType: "service",
+        host: "localhost",
+        id: "resolved",
+        interval: "30s",
+        logLevel: "debug",
+        maxConcurrentChecks: 20,
+        retention: "24h",
+        token: "abc",
+        TOKEN_KEY: "TOKEN",
+        type: "cmd",
+      },
     });
 
     expect(result.issues).toHaveLength(0);
     const config = result.config as {
       defaults: { interval: string };
-      server: { host: string };
-      targets: Array<{ cmd: { args: string[]; env: Record<string, string> }; id: string; type: string }>;
+      probes: { execution: { maxConcurrentChecks: number } };
+      server: { host: string; logging: { level: string }; storage: { retention: string } };
+      targets: Array<{
+        cmd: { args: string[]; env: Record<string, string> };
+        expect: { rows: Array<{ id: { equals: number }; type: { equals: string } }> };
+        id: string;
+        type: string;
+      }>;
+      variables: { host: string };
     };
-    expect(config.server.host).toBe("${host}");
+    expect(config.server.host).toBe("localhost");
+    expect(config.server.logging.level).toBe("debug");
+    expect(config.server.storage.retention).toBe("24h");
+    expect(config.probes.execution.maxConcurrentChecks).toBe(20);
+    expect(config.variables.host).toBe("localhost");
     expect(config.defaults.interval).toBe("${interval}");
     expect(config.targets[0]!.id).toBe("${id}");
     expect(config.targets[0]!.type).toBe("${type}");
     expect(config.targets[0]!.cmd.args[1]).toBe("localhost");
-    expect(config.targets[0]!.cmd.env["TOKEN"]).toBe("abc");
+    expect(config.targets[0]!.cmd.env["${TOKEN_KEY}"]).toBe("abc");
+    expect(config.targets[0]!.expect.rows[0]!.id.equals).toBe(1);
+    expect(config.targets[0]!.expect.rows[0]!.type.equals).toBe("service");
   });
 
   test("默认值推断为 boolean（true/false）", () => {
@@ -220,7 +247,39 @@ describe("config variables", () => {
     expect(typeof http2["ignoreSSL"]).toBe("boolean");
   });
 
-  test("server.storage 段不替换", () => {
+  test("空默认值和空环境变量保持字符串空值", () => {
+    const original = process.env["EMPTY_ENV_VALUE"];
+    process.env["EMPTY_ENV_VALUE"] = "";
+
+    try {
+      const result = resolveVariables({
+        server: { listen: { host: "${EMPTY_ENV_VALUE}" }, logging: { file: { path: "${OPTIONAL_LOG_PATH|}" } } },
+        targets: [
+          {
+            http: { body: "${OPTIONAL_BODY|}", url: "${HOST|localhost}" },
+            id: "empty-values",
+            type: "http",
+          },
+        ],
+      });
+
+      expect(result.issues).toHaveLength(0);
+      const config = result.config as {
+        server: { listen: { host: unknown }; logging: { file: { path: unknown } } };
+        targets: Array<{ http: { body: unknown } }>;
+      };
+      expect(config.server.listen.host).toBe("");
+      expect(typeof config.server.listen.host).toBe("string");
+      expect(config.server.logging.file.path).toBe("");
+      expect(typeof config.server.logging.file.path).toBe("string");
+      expect(config.targets[0]!.http.body).toBe("");
+      expect(typeof config.targets[0]!.http.body).toBe("string");
+    } finally {
+      restoreEnv("EMPTY_ENV_VALUE", original);
+    }
+  });
+
+  test("server.storage 段支持替换", () => {
     const result = resolveVariables({
       server: { storage: { retention: "${retention}" } },
       targets: [
@@ -235,10 +294,10 @@ describe("config variables", () => {
 
     expect(result.issues).toHaveLength(0);
     const config = result.config as { server: { storage: { retention: string } } };
-    expect(config.server.storage.retention).toBe("${retention}");
+    expect(config.server.storage.retention).toBe("24h");
   });
 
-  test("probes 段不替换", () => {
+  test("probes 段支持替换", () => {
     const result = resolveVariables({
       probes: { execution: { maxConcurrentChecks: "${maxConcurrentChecks}" } },
       targets: [
@@ -248,15 +307,15 @@ describe("config variables", () => {
           type: "http",
         },
       ],
-      variables: { host: "https://example.com", maxConcurrentChecks: "20" },
+      variables: { host: "https://example.com", maxConcurrentChecks: 20 },
     });
 
     expect(result.issues).toHaveLength(0);
-    const config = result.config as { probes: { execution: { maxConcurrentChecks: string } } };
-    expect(config.probes.execution.maxConcurrentChecks).toBe("${maxConcurrentChecks}");
+    const config = result.config as { probes: { execution: { maxConcurrentChecks: number } } };
+    expect(config.probes.execution.maxConcurrentChecks).toBe(20);
   });
 
-  test("server.logging 段不替换", () => {
+  test("server.logging 段支持替换", () => {
     const result = resolveVariables({
       server: { logging: { level: "${logLevel}" } },
       targets: [
@@ -271,7 +330,7 @@ describe("config variables", () => {
 
     expect(result.issues).toHaveLength(0);
     const config = result.config as { server: { logging: { level: string } } };
-    expect(config.server.logging.level).toBe("${logLevel}");
+    expect(config.server.logging.level).toBe("debug");
   });
 
   test("variables 段为非对象时报错", () => {