fix(task): treat case-insensitive Name-N labels as handle echoes

The exact-echo check used accent-insensitive compare, but the collision
suffix path was a case-sensitive startsWith. AuthLoader-3 vs authloader
therefore leaked through as a real description.

packages/coding-agent/src/task/label.ts

@@ -13,8 +13,11 @@ const TASK_LABEL_SYSTEM_PROMPT = prompt.render(taskLabelSystemPrompt);
 export function labelEchoesHandle(handle: string | undefined, label: string): boolean {
 	if (!handle) return false;
 	if (label.localeCompare(handle, undefined, { sensitivity: "accent" }) === 0) return true;
-	const suffix = handle.startsWith(`${label}-`) ? handle.slice(label.length + 1) : "";
-	return /^\d+$/.test(suffix);
+	const separator = handle.lastIndexOf("-");
+	if (separator <= 0) return false;
+	const prefix = handle.slice(0, separator);
+	const suffix = handle.slice(separator + 1);
+	return /^\d+$/.test(suffix) && prefix.localeCompare(label, undefined, { sensitivity: "accent" }) === 0;
 }
 
 /** Compresses a delegated assignment into a one-sentence UI label via the tiny title model — fired by the executor spawn path because the task wire schema no longer carries a `description`; null on empty input or failure. */

packages/coding-agent/test/subagent-hud-render.test.ts

@@ -141,6 +141,16 @@ describe("subagent HUD lines", () => {
 		expect(collision).toMatch(/AuthLoader-3.*scout/);
 		expect(collision).not.toContain("AuthLoader-3: AuthLoader");
 
+		const mixedCase = render([
+			makeSession({
+				id: "AuthLoader-3",
+				agent: "scout",
+				description: "authloader",
+			}),
+		]);
+		expect(mixedCase).toContain("AuthLoader-3");
+		expect(mixedCase).not.toContain("AuthLoader-3: authloader");
+
 		const defaultWorker = render([
 			makeSession({ id: "SchemaMigrator", agent: "task", description: "Migrate users" }),
 		]);

packages/coding-agent/test/task-label.test.ts

@@ -2,7 +2,7 @@ import { afterEach, describe, expect, it, vi } from "bun:test";
 import type { Api, Model } from "@oh-my-pi/pi-ai";
 import * as ai from "@oh-my-pi/pi-ai";
 import { getBundledModel } from "@oh-my-pi/pi-catalog/models";
-import { generateTaskLabel } from "@oh-my-pi/pi-coding-agent/task/label";
+import { generateTaskLabel, labelEchoesHandle } from "@oh-my-pi/pi-coding-agent/task/label";
 
 function getModelOrThrow(id: string): Model<Api> {
 	const model = getBundledModel("anthropic", id);
@@ -93,4 +93,11 @@ describe("task label generation", () => {
 		);
 		expect(labeled).toBe("Sleep then reply done");
 	});
+
+	it("treats a case-insensitive Name-N collision as an echoed handle", () => {
+		expect(labelEchoesHandle("AuthLoader-3", "authloader")).toBe(true);
+		expect(labelEchoesHandle("AuthLoader-3", "AuthLoader")).toBe(true);
+		expect(labelEchoesHandle("AuthLoader", "authloader")).toBe(true);
+		expect(labelEchoesHandle("AuthLoader-3", "Migrate users")).toBe(false);
+	});
 });