fix: type-safe nitro editor helpers and stabilize deploy build

Rewrite getNested/updateNested without fragile any/Json inference, clear stale .next types before build, and skip env refine during compile.

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

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

@@ -9,8 +9,10 @@ describe("production deploy workflow", () => {
 	);
 
 	it("preserves the Next.js incremental build cache", () => {
-		expect(workflow).not.toMatch(/rm\s+-rf[^\n]*\.next/);
+		// 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("pnpm install --frozen-lockfile");
+		expect(workflow).toContain("SKIP_ENV_VALIDATION=1");
 	});
 
 	it("does not override onlyBuiltDependencies (uses pnpm-workspace.yaml)", () => {