test(api): achieve 100% coverage across all routes, middleware, and services

- Add full test suite for frontend.ts (POST /log and POST /error)
- Add error-path tests to all route handlers to cover catch blocks
  triggered by Prisma rejections
- Add non-Error throw tests to cover the `new Error(String(error))`
  ternary false branch in middleware, services, and route catch handlers
- Suppress unreachable outer catch in about.ts with v8 ignore (fetchReleases
  swallows all errors internally, making the outer catch genuinely dead code)

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

@@ -420,6 +420,45 @@ describe("game route", () => {
     });
   });
 
+  describe("GET /load error path", () => {
+    it("returns 500 when the database throws during load", async () => {
+      vi.mocked(prisma.gameState.findUnique).mockRejectedValueOnce(new Error("DB error"));
+      vi.mocked(prisma.player.findUnique).mockRejectedValueOnce(new Error("DB error"));
+      const res = await app.fetch(new Request("http://localhost/game/load"));
+      expect(res.status).toBe(500);
+    });
+
+    it("returns 500 when the database throws a non-Error value during load", async () => {
+      vi.mocked(prisma.gameState.findUnique).mockRejectedValueOnce("raw string error");
+      vi.mocked(prisma.player.findUnique).mockRejectedValueOnce("raw string error");
+      const res = await app.fetch(new Request("http://localhost/game/load"));
+      expect(res.status).toBe(500);
+    });
+  });
+
+  describe("POST /save error path", () => {
+    const save = (body: Record<string, unknown>) =>
+      app.fetch(new Request("http://localhost/game/save", {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify(body),
+      }));
+
+    it("returns 500 when the database throws during save", async () => {
+      const state = makeState();
+      vi.mocked(prisma.gameState.findUnique).mockRejectedValueOnce(new Error("DB error"));
+      const res = await save({ state });
+      expect(res.status).toBe(500);
+    });
+
+    it("returns 500 when the database throws a non-Error value during save", async () => {
+      const state = makeState();
+      vi.mocked(prisma.gameState.findUnique).mockRejectedValueOnce("raw string error");
+      const res = await save({ state });
+      expect(res.status).toBe(500);
+    });
+  });
+
   describe("POST /reset", () => {
     const reset = () =>
       app.fetch(new Request("http://localhost/game/reset", { method: "POST" }));
@@ -450,5 +489,17 @@ describe("game route", () => {
       const body = await res.json() as { signature: string | undefined };
       expect(typeof body.signature).toBe("string");
     });
+
+    it("returns 500 when the database throws during reset", async () => {
+      vi.mocked(prisma.player.findUnique).mockRejectedValueOnce(new Error("DB error"));
+      const res = await reset();
+      expect(res.status).toBe(500);
+    });
+
+    it("returns 500 when the database throws a non-Error value during reset", async () => {
+      vi.mocked(prisma.player.findUnique).mockRejectedValueOnce("raw string error");
+      const res = await reset();
+      expect(res.status).toBe(500);
+    });
   });
 });