fix: make useServerAction accept void-returning actions and remove dead queryCount

- Type run()'s action param as Promise<unknown> and cast result (Biome strips void from unions)
- Remove unused queryCount field increment in DbService (dead code)
- Reformat theme-contrast test pair assertions

src/lib/foundation/database.ts

@@ -19,7 +19,6 @@ export class DbService {
 	private readonly client: PrismaClient;
 	private lastHealthCheck = 0;
 	private healthCache: HealthStatus | null = null;
-	private queryCount = 0;
 	private readonly healthTtlMs = 10_000;
 
 	constructor() {
@@ -106,7 +105,6 @@ export class DbService {
 	}
 
 	async execute<T>(fn: (client: PrismaClient) => Promise<T>): Promise<T> {
-		this.queryCount++;
 		try {
 			return await fn(this.client);
 		} catch (cause) {

src/lib/theme-contrast.test.ts

@@ -166,14 +166,14 @@ describe("derivePublicForegrounds", () => {
 			for (const palette of [preset.light, preset.dark]) {
 				const result = derivePublicForegrounds(palette);
 				for (const name of required) {
-				const pair = result.pairs.find(
-					(candidate) => candidate.name === name,
-				);
-				expect(pair, `missing ${name}`).toBeDefined();
-				expect(
-					contrastRatio(pair!.foreground, pair!.background),
-					name,
-				).toBeGreaterThanOrEqual(4.5);
+					const pair = result.pairs.find(
+						(candidate) => candidate.name === name,
+					);
+					expect(pair, `missing ${name}`).toBeDefined();
+					expect(
+						contrastRatio(pair?.foreground, pair?.background),
+						name,
+					).toBeGreaterThanOrEqual(4.5);
 				}
 			}
 		}