fix: tighten target error hint coverage

src/infra/outbound/target-errors.test.ts

@@ -19,6 +19,16 @@ describe("target error helpers", () => {
     );
   });
 
+  it("treats blank hints the same as no hint", () => {
+    expect(missingTargetMessage("Slack", "   ")).toBe("Delivering to Slack requires target");
+    expect(ambiguousTargetMessage("Discord", "general", "   ")).toBe(
+      'Ambiguous target "general" for Discord. Provide a unique name or an explicit id.',
+    );
+    expect(unknownTargetMessage("Discord", "general", "   ")).toBe(
+      'Unknown target "general" for Discord.',
+    );
+  });
+
   it("formats ambiguous and unknown target messages with labeled hints", () => {
     expect(ambiguousTargetMessage("Discord", "general")).toBe(
       'Ambiguous target "general" for Discord. Provide a unique name or an explicit id.',

src/infra/outbound/target-errors.ts

@@ -23,8 +23,9 @@ export function unknownTargetError(provider: string, raw: string, hint?: string)
 }
 
 function formatTargetHint(hint?: string, withLabel = false): string {
-  if (!hint) {
+  const normalized = hint?.trim();
+  if (!normalized) {
     return "";
   }
-  return withLabel ? ` Hint: ${hint}` : ` ${hint}`;
+  return withLabel ? ` Hint: ${normalized}` : ` ${normalized}`;
 }