test(web): cover instance store CRUD and legacy migration

Closes the multi-instance coverage gap: add (first becomes active, later adds
don't steal focus, insertion order), switch (incl. unknown-id no-op), delete
(active->first-remaining fallback, non-active unchanged, last clears active),
update (patch + unknown-id no-op), active config, and legacy-key migration.

packages/web/src/test/instances.test.ts

@@ -0,0 +1,125 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import {
+	addInstance,
+	deleteInstance,
+	getActiveInstance,
+	loadConfig,
+	loadStore,
+	setActiveInstance,
+	updateInstance,
+} from "@/lib/config";
+
+const STORE_KEY = "openconcho:instances";
+const LEGACY_KEY = "openconcho:config";
+
+beforeEach(() => localStorage.clear());
+afterEach(() => localStorage.clear());
+
+describe("instance store — add + active selection", () => {
+	it("makes the first added instance active", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		expect(loadStore().activeId).toBe(a.id);
+	});
+
+	it("does not steal active focus when adding more instances", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		addInstance({ name: "B", baseUrl: "https://b.example.net", token: "" });
+		expect(loadStore().activeId).toBe(a.id);
+	});
+
+	it("appends instances in insertion order", () => {
+		addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		addInstance({ name: "B", baseUrl: "https://b.example.net", token: "" });
+		expect(loadStore().instances.map((i) => i.name)).toEqual(["A", "B"]);
+	});
+});
+
+describe("instance store — switching active", () => {
+	it("switches the active instance", () => {
+		addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		const b = addInstance({ name: "B", baseUrl: "https://b.example.net", token: "" });
+		setActiveInstance(b.id);
+		expect(getActiveInstance()?.id).toBe(b.id);
+	});
+
+	it("ignores an unknown id", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		setActiveInstance("does-not-exist");
+		expect(getActiveInstance()?.id).toBe(a.id);
+	});
+});
+
+describe("instance store — deletion", () => {
+	it("falls back to the first remaining when the active instance is deleted", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		const b = addInstance({ name: "B", baseUrl: "https://b.example.net", token: "" });
+		setActiveInstance(b.id);
+		deleteInstance(b.id);
+		expect(loadStore().activeId).toBe(a.id);
+	});
+
+	it("leaves the active id unchanged when a non-active instance is deleted", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		const b = addInstance({ name: "B", baseUrl: "https://b.example.net", token: "" });
+		deleteInstance(b.id);
+		expect(getActiveInstance()?.id).toBe(a.id);
+	});
+
+	it("clears the active id when the last instance is removed", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		deleteInstance(a.id);
+		expect(loadStore().activeId).toBeNull();
+	});
+
+	it("returns null config once every instance is gone", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		deleteInstance(a.id);
+		expect(loadConfig()).toBeNull();
+	});
+});
+
+describe("instance store — update", () => {
+	it("patches the named fields", () => {
+		const a = addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		updateInstance(a.id, { name: "Renamed", token: "sk-1" });
+		expect(loadStore().instances[0]).toMatchObject({ name: "Renamed", token: "sk-1" });
+	});
+
+	it("no-ops on an unknown id", () => {
+		addInstance({ name: "A", baseUrl: "https://a.example.net", token: "" });
+		updateInstance("nope", { name: "X" });
+		expect(loadStore().instances[0].name).toBe("A");
+	});
+});
+
+describe("instance store — active config", () => {
+	it("reflects the active instance's url and token", () => {
+		addInstance({ name: "A", baseUrl: "https://a.example.net", token: "sk-a" });
+		expect(loadConfig()).toEqual({ baseUrl: "https://a.example.net", token: "sk-a" });
+	});
+});
+
+describe("instance store — legacy migration", () => {
+	it("migrates the legacy single-config key into the instances store", () => {
+		localStorage.setItem(
+			LEGACY_KEY,
+			JSON.stringify({ baseUrl: "https://legacy.example.net", token: "sk-legacy" }),
+		);
+		const store = loadStore();
+		expect(store.instances[0]).toMatchObject({
+			name: "Default",
+			baseUrl: "https://legacy.example.net",
+			token: "sk-legacy",
+		});
+	});
+
+	it("removes the legacy key after migrating", () => {
+		localStorage.setItem(
+			LEGACY_KEY,
+			JSON.stringify({ baseUrl: "https://legacy.example.net", token: "" }),
+		);
+		loadStore();
+		expect(localStorage.getItem(LEGACY_KEY)).toBeNull();
+		expect(localStorage.getItem(STORE_KEY)).toBeTruthy();
+	});
+});