fix(issue): showNextAction !ctx.hasUI guard misses headless RPC mode where hasUI is truthy but no human input is possible (next-action-ui.js:70)

src/resources/extensions/shared/next-action-ui.ts

@@ -118,11 +118,9 @@ export async function showNextAction(
 		}
 	});
 
-	// Headless guard: when no UI is bound (noOpUIContext), ctx.ui.custom() resolves
-	// to undefined immediately, and ctx.ui.select() does the same. Skip both and
-	// return the safe default so callers don't await two no-op promises before
-	// reaching a deterministic "not_yet". Lockup #5125 root protection.
-	if (!ctx.hasUI) {
+	// Headless/non-interactive guard: avoid emitting interactive select requests
+	// in contexts where no human can answer (no UI, RPC/headless shims).
+	if (!isInteractiveUIContext(ctx)) {
 		return "not_yet";
 	}
 
@@ -218,3 +216,11 @@ export async function showNextAction(
 
 	return result;
 }
+
+function isInteractiveUIContext(ctx: ExtensionCommandContext): boolean {
+	if (!ctx.hasUI) return false;
+	if (process.env.GSD_HEADLESS === "1") return false;
+	const uiMode = (ctx.ui as { mode?: string } | undefined)?.mode;
+	if (uiMode === "rpc" || uiMode === "headless") return false;
+	return true;
+}

src/resources/extensions/shared/tests/next-action-ui-hasui.test.ts

@@ -81,6 +81,38 @@ describe("showNextAction ctx.hasUI guard (#5125 lockup root protection)", () =>
     assert.equal(result, "alpha", "fallback should map the picked label back to the chosen action id");
   });
 
+  it("returns 'not_yet' immediately when UI mode is rpc even if ctx.hasUI is true", async () => {
+    let customCalled = 0;
+    let selectCalled = 0;
+
+    const ctx = {
+      hasUI: true,
+      ui: {
+        mode: "rpc",
+        custom: async () => {
+          customCalled++;
+          return undefined as never;
+        },
+        select: async () => {
+          selectCalled++;
+          return undefined;
+        },
+      },
+    };
+
+    const result = await showNextAction(ctx as any, {
+      title: "GSD — test",
+      actions: [
+        { id: "alpha", label: "Alpha", description: "first", recommended: true },
+        { id: "beta", label: "Beta", description: "second" },
+      ],
+    });
+
+    assert.equal(result, "not_yet", "rpc-backed UI is non-interactive for next-action");
+    assert.equal(customCalled, 0, "ctx.ui.custom must not be called in rpc mode");
+    assert.equal(selectCalled, 0, "ctx.ui.select must not be called in rpc mode");
+  });
+
   it("returns the resolved id when ctx.ui.custom completes normally", async () => {
     let selectCalled = 0;