perf(deploy): keep .next/cache while clearing stale generated types

Nuclear src replace already guarantees clean sources; restoring the build cache speeds deploys without reintroducing sticky typecheck ghosts.

Co-authored-by: Cursor <[email protected]>

src/lib/deploy-workflow-contract.test.ts

@@ -8,8 +8,10 @@ describe("production deploy workflow", () => {
 		"utf8",
 	);
 
-	it("wipes .next before build to avoid stale Next typecheck caches", () => {
-		expect(workflow).toContain("rm -rf .output dist .next");
+	it("preserves the Next.js incremental build cache", () => {
+		// May clear .next/types or .next/dev, but must not wipe the whole .next tree.
+		expect(workflow).not.toMatch(/rm\s+-rf\s+\.next(?:\s|$)/);
+		expect(workflow).toContain("rm -rf .output dist .next/types .next/dev");
 		expect(workflow).toContain("pnpm install --frozen-lockfile");
 		expect(workflow).toContain("SKIP_ENV_VALIDATION=1");
 	});