diff --git a/.gitea/workflows/deploy.yaml b/.gitea/workflows/deploy.yaml
index 290dcdd3..b795a530 100644
--- a/.gitea/workflows/deploy.yaml
+++ b/.gitea/workflows/deploy.yaml
@@ -66,6 +66,10 @@ jobs:
           pnpm test
 
           # 7. Next.js Build
+          # Skip env refine during compile/page-data; runtime still validates via env.ts.
+          # Drop stale generated types that can diverge from source after incremental builds.
+          rm -rf .next/types .next/dev
+          export SKIP_ENV_VALIDATION=1
           pnpm build
 
           # 8. Fix ownership: Build first, THEN set permissions for the web server
diff --git a/src/app/admin/import/furni/nitro-editor-dialog.tsx b/src/app/admin/import/furni/nitro-editor-dialog.tsx
index 74860c70..352b0fd7 100644
--- a/src/app/admin/import/furni/nitro-editor-dialog.tsx
+++ b/src/app/admin/import/furni/nitro-editor-dialog.tsx
@@ -39,30 +39,51 @@ interface NitroEditorDialogProps {
 	onOpenChange: (open: boolean) => void;
 }
 
-// biome-ignore lint/suspicious/noExplicitAny: explicitly chosen here, see surrounding code
-function updateNested(obj: any, path: string, value: unknown): any {
-	const clone = JSON.parse(JSON.stringify(obj));
+function updateNested(
+	obj: Record<string, unknown>,
+	path: string,
+	value: unknown,
+): Record<string, unknown> {
+	const clone = JSON.parse(JSON.stringify(obj)) as Record<string, unknown>;
 	const keys = path.split(".");
-	let current = clone;
+	let current: Record<string, unknown> = clone;
 	for (let i = 0; i < keys.length - 1; i++) {
-		if (!current[keys[i]]) current[keys[i]] = {};
-		current = current[keys[i]];
+		const key = keys[i];
+		const next = current[key];
+		if (next == null || typeof next !== "object" || Array.isArray(next)) {
+			current[key] = {};
+		}
+		current = current[key] as Record<string, unknown>;
 	}
 	current[keys[keys.length - 1]] = value;
 	return clone;
 }
 
-// biome-ignore lint/suspicious/noExplicitAny: explicitly chosen here, see surrounding code
-function getNested(obj: any, path: string, fallback?: unknown): any {
+function getNested(
+	obj: unknown,
+	path: string,
+	fallback?: unknown,
+): unknown {
 	const keys = path.split(".");
-	let current = obj;
+	let current: unknown = obj;
 	for (const key of keys) {
 		if (current == null || typeof current !== "object") return fallback;
-		current = current[key];
+		current = (current as Record<string, unknown>)[key];
 	}
 	return current ?? fallback;
 }
 
+function patchMetadata(
+	prev: unknown,
+	path: string,
+	value: unknown,
+): unknown {
+	if (prev == null || typeof prev !== "object" || Array.isArray(prev)) {
+		return prev;
+	}
+	return updateNested(prev as Record<string, unknown>, path, value);
+}
+
 const ALL_DIRECTIONS = [0, 1, 2, 3, 4, 5, 6, 7];
 const DIR_LABELS = ["N", "NE", "E", "SE", "S", "SW", "W", "NW"];
 
@@ -220,33 +241,33 @@ export function NitroEditorDialog({
 
 	// ── Visual tab helpers ──
 
-	const dims = metadata
-		? getNested(metadata, "logic.model.dimensions", { x: 1, y: 1, z: 0 })
-		: { x: 1, y: 1, z: 0 };
-	const directions: number[] = metadata
-		? getNested(metadata, "logic.model.directions", [0])
-		: [0];
+	const dims = (
+		metadata
+			? getNested(metadata, "logic.model.dimensions", { x: 1, y: 1, z: 0 })
+			: { x: 1, y: 1, z: 0 }
+	) as { x: number; y: number; z: number };
+	const directions = (
+		metadata ? getNested(metadata, "logic.model.directions", [0]) : [0]
+	) as number[];
 
 	const setDim = (axis: "x" | "y" | "z", value: string) => {
 		const num =
 			axis === "z" ? parseFloat(value) || 0 : parseInt(value, 10) || 0;
 		setMetadata((prev: unknown) =>
-			updateNested(prev, `logic.model.dimensions.${axis}`, num),
+			patchMetadata(prev, `logic.model.dimensions.${axis}`, num),
 		);
 	};
 
 	const toggleDirection = (dir: number) => {
-		const current: number[] = getNested(
-			metadata,
-			"logic.model.directions",
-			[0],
-		);
+		const current = getNested(metadata, "logic.model.directions", [
+			0,
+		]) as number[];
 		const next = current.includes(dir)
 			? current.filter((d: number) => d !== dir)
 			: [...current, dir].sort((a: number, b: number) => a - b);
 		if (next.length === 0) return;
 		setMetadata((prev: unknown) =>
-			updateNested(prev, "logic.model.directions", next),
+			patchMetadata(prev, "logic.model.directions", next),
 		);
 	};
 
@@ -549,7 +570,7 @@ export function NitroEditorDialog({
 											value={metadata.visualizationType || ""}
 											onChange={(e) =>
 												setMetadata((prev: unknown) =>
-													updateNested(
+													patchMetadata(
 														prev,
 														"visualizationType",
 														e.target.value,
@@ -571,7 +592,7 @@ export function NitroEditorDialog({
 											value={metadata.logicType || ""}
 											onChange={(e) =>
 												setMetadata((prev: unknown) =>
-													updateNested(prev, "logicType", e.target.value),
+													patchMetadata(prev, "logicType", e.target.value),
 												)
 											}
 											className="mt-1 font-mono text-sm"
@@ -622,7 +643,7 @@ export function NitroEditorDialog({
 															value={(layer.z as number) ?? 0}
 															onChange={(e) => {
 																setMetadata((prev: unknown) =>
-																	updateNested(
+																	patchMetadata(
 																		prev,
 																		`visualizations.${viz64Index}.layers.${layerId}.z`,
 																		parseInt(e.target.value, 10) || 0,
@@ -638,7 +659,7 @@ export function NitroEditorDialog({
 															value={(layer.alpha as number) ?? 255}
 															onChange={(e) => {
 																setMetadata((prev: unknown) =>
-																	updateNested(
+																	patchMetadata(
 																		prev,
 																		`visualizations.${viz64Index}.layers.${layerId}.alpha`,
 																		parseInt(e.target.value, 10) || 0,
@@ -652,7 +673,7 @@ export function NitroEditorDialog({
 															placeholder="—"
 															onChange={(e) => {
 																setMetadata((prev: unknown) =>
-																	updateNested(
+																	patchMetadata(
 																		prev,
 																		`visualizations.${viz64Index}.layers.${layerId}.ink`,
 																		e.target.value || undefined,
@@ -737,7 +758,7 @@ export function NitroEditorDialog({
 																				.slice(0, 6);
 																			const num = parseInt(hex, 16) || 0;
 																			setMetadata((prev: unknown) =>
-																				updateNested(
+																				patchMetadata(
 																					prev,
 																					`visualizations.${viz64Index}.colors.${colorId}.${layerId}.color`,
 																					num,
diff --git a/src/lib/deploy-workflow-contract.test.ts b/src/lib/deploy-workflow-contract.test.ts
index fda6036b..65c72c51 100644
--- a/src/lib/deploy-workflow-contract.test.ts
+++ b/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)", () => {