feat: add opt-out toggle for prestige bot announcements

Adds enablePrestigeAnnouncements to ProfileSettings (defaults to true).
The prestige route now checks this setting before posting the Discord
webhook, and the edit profile modal exposes a toggle in the Sounds &
Notifications section so players can opt out.

Closes #169

apps/api/test/routes/prestige.spec.ts

@@ -7,7 +7,7 @@ import type { GameState } from "@elysium/types";
 
 vi.mock("../../src/db/client.js", () => ({
   prisma: {
-    player: { update: vi.fn() },
+    player: { findUnique: vi.fn(), update: vi.fn() },
     gameState: { findUnique: vi.fn(), update: vi.fn(), updateMany: vi.fn() },
   },
 }));
@@ -47,7 +47,7 @@ const makeState = (overrides: Partial<GameState> = {}): GameState => ({
 describe("prestige route", () => {
   let app: Hono;
   let prisma: {
-    player: { update: ReturnType<typeof vi.fn> };
+    player: { findUnique: ReturnType<typeof vi.fn>; update: ReturnType<typeof vi.fn> };
     gameState: { findUnique: ReturnType<typeof vi.fn>; update: ReturnType<typeof vi.fn>; updateMany: ReturnType<typeof vi.fn> };
   };
 
@@ -128,6 +128,18 @@ describe("prestige route", () => {
       const body = await res.json() as { runestones: number; newPrestigeCount: number };
       expect(body.newPrestigeCount).toBe(1);
     });
+
+    it("skips webhook when enablePrestigeAnnouncements is false", async () => {
+      const { postMilestoneWebhook } = await import("../../src/services/webhook.js");
+      const state = makeState();
+      vi.mocked(prisma.gameState.findUnique).mockResolvedValueOnce({ state, updatedAt: 0 } as never);
+      vi.mocked(prisma.gameState.updateMany).mockResolvedValueOnce({ count: 1 } as never);
+      vi.mocked(prisma.player.update).mockResolvedValueOnce({} as never);
+      vi.mocked(prisma.player.findUnique).mockResolvedValueOnce({ profileSettings: { enablePrestigeAnnouncements: false } } as never);
+      const res = await post("");
+      expect(res.status).toBe(200);
+      expect(postMilestoneWebhook).not.toHaveBeenCalledWith(expect.anything(), "prestige", expect.anything());
+    });
   });
 
   describe("POST /buy-upgrade", () => {