tests: add coverage for src/actions/ (15 files) and src/lib/{admin,auth} (3 files)

- src/actions coverage: 2.4% -> 13.55%
- src/lib/admin coverage: 44.3% -> 84.81%
- src/lib/auth coverage: 90.52%
- vitest.config.ts: exclude .next.prev/ from test discovery

src/actions/emulator.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it, vi } from "vitest";
+import { PERMS } from "@/lib/permissions";
+import { prisma } from "@/lib/prisma";
+import { adminAction } from "@/lib/safe-action";
+import { actionOk } from "@/lib/safe-action-shared";
+import { logAudit } from "@/lib/services/audit";
+import { rcon } from "@/lib/services/rcon";
+
+vi.mock("@/lib/permissions", () => ({
+	PERMS: { SETTINGS_EDIT: "settings.edit" },
+}));
+vi.mock("@/lib/prisma", () => ({
+	prisma: { emulatorSettings: { upsert: vi.fn() } },
+}));
+vi.mock("@/lib/safe-action", () => ({
+	adminAction: vi.fn((_opts: unknown, fn: Function) => fn),
+}));
+vi.mock("@/lib/safe-action-shared", () => ({ actionOk: vi.fn(() => "ok") }));
+vi.mock("@/lib/services/audit", () => ({ logAudit: vi.fn() }));
+vi.mock("@/lib/services/rcon", () => ({ rcon: { updateConfig: vi.fn() } }));
+
+describe("saveEmulatorSettings", () => {
+	it("saves settings and calls rcon update", async () => {
+		vi.mocked(prisma.emulatorSettings.upsert).mockResolvedValue({} as never);
+		const handler = (await import("./emulator").then(
+			(m) => m.saveEmulatorSettings,
+		)) as unknown as (ctx: {
+			data: { settings: Record<string, string> };
+			session: { user: { id: string } };
+		}) => Promise<string>;
+
+		const result = await handler({
+			data: { settings: { key1: "val1", key2: "val2" } },
+			session: { user: { id: "1" } },
+		});
+
+		expect(prisma.emulatorSettings.upsert).toHaveBeenCalledTimes(2);
+		expect(rcon.updateConfig).toHaveBeenCalled();
+		expect(result).toBe("ok");
+	});
+});