test: tighten timeout signature assertions

src/agents/bash-tools.exec-foreground-failures.test.ts

@@ -48,7 +48,8 @@ describe("exec foreground failures", () => {
       exitCode: null,
       aggregated: "",
     });
-    expect((result.details as { durationMs?: number }).durationMs).toEqual(expect.any(Number));
+    expect((result.details as { durationMs?: number }).durationMs).toBeTypeOf("number");
+    expect((result.details as { durationMs?: number }).durationMs).toBeGreaterThanOrEqual(0);
   });
 
   it("rejects invalid host values before launching a command", async () => {

src/agents/bootstrap-budget.test.ts

@@ -211,7 +211,8 @@ describe("bootstrap prompt warnings", () => {
       mode: "once",
     });
     expect(first.warningShown).toBe(true);
-    expect(first.signature).toEqual(expect.any(String));
+    expect(first.signature).toBeTypeOf("string");
+    expect(first.signature).not.toBe("");
     expect(JSON.parse(first.signature ?? "{}")).toMatchObject({
       bootstrapMaxChars: 120,
       bootstrapTotalMaxChars: 200,

src/infra/push-apns.test.ts

@@ -589,7 +589,8 @@ describe("push APNs send semantics", () => {
         },
       },
     });
-    expect(sent?.signature).toEqual(expect.any(String));
+    expect(sent?.signature).toBeTypeOf("string");
+    expect(sent?.signature).not.toBe("");
     expect(result).toMatchObject({
       ok: true,
       status: 202,