test: make coverage opt-in and ratchet thresholds to the measured floor

Coverage was enabled by default, which forced v8 instrumentation on every run
and made a focused `vitest run <file>` fail the global thresholds that a
single file can never satisfy. `pnpm test:coverage` now opts in explicitly
while `pnpm test` stays fast.

Thresholds ratcheted from 36/29/30/37 to the measured full-suite floor of
37/30/31/38, so a drop in coverage fails again. Also drops a stale comment
about a parent Laravel repo and a dead .next.prev exclude from the config.

vitest.config.ts

@@ -1,8 +1,9 @@
 import { fileURLToPath } from "node:url";
 import { defineConfig } from "vitest/config";
 
-// Local config so Vitest does not walk up into the parent Laravel repo's
-// vite.config.js (this app lives inside the Laravel project tree).
+// Project-local config: keeps the `@/` alias, the server-only stub and the
+// env fallbacks with the repo instead of relying on whatever vite config a
+// parent directory happens to provide.
 export default defineConfig({
 	resolve: {
 		alias: {
@@ -26,22 +27,24 @@ export default defineConfig({
 			DATABASE_URL: "mysql://root:root@localhost:3306/test",
 		},
 		testTimeout: 10000,
-		exclude: [
-			"integration/**",
-			"e2e/**",
-			"node_modules/**",
-			".next/**",
-			".next.prev/**",
-		],
+		exclude: ["integration/**", "e2e/**", "node_modules/**", ".next/**"],
 		coverage: {
-			enabled: true,
+			// Off unless asked for (`pnpm test:coverage` passes
+			// `--coverage.enabled=true`): a focused `vitest run <file>` should
+			// not fail the global thresholds it cannot possibly meet, and
+			// measuring v8 coverage on every run costs real time.
+			enabled: false,
 			provider: "v8",
 			reporter: ["text", "lcov", "html"],
+			// Ratchet floor: measured 37.14 / 30.09 / 31.74 / 38.13 on the full
+			// suite (statements/branches/functions/lines). Rounded down so only
+			// a real regression fails the build — raise these to the new
+			// measured floor whenever coverage improves.
 			thresholds: {
-				statements: 36,
-				branches: 29,
-				functions: 30,
-				lines: 37,
+				statements: 37,
+				branches: 30,
+				functions: 31,
+				lines: 38,
 			},
 			include: ["src/**/*.{ts,tsx}"],
 			exclude: [