refactor(security): make empty allowlist behavior explicit

extensions/bluebubbles/src/targets.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 import {
+  isAllowedBlueBubblesSender,
   looksLikeBlueBubblesTargetId,
   normalizeBlueBubblesMessagingTarget,
   parseBlueBubblesTarget,
@@ -181,3 +182,21 @@ describe("parseBlueBubblesAllowTarget", () => {
     });
   });
 });
+
+describe("isAllowedBlueBubblesSender", () => {
+  it("denies when allowFrom is empty", () => {
+    const allowed = isAllowedBlueBubblesSender({
+      allowFrom: [],
+      sender: "+15551234567",
+    });
+    expect(allowed).toBe(false);
+  });
+
+  it("allows wildcard entries", () => {
+    const allowed = isAllowedBlueBubblesSender({
+      allowFrom: ["*"],
+      sender: "+15551234567",
+    });
+    expect(allowed).toBe(true);
+  });
+});