fix: harden update pipeline and restore a clean production build

- update-Nitrov3.sh: build CMS into .next-staging and swap atomically so a
  failed build never takes the live site down; auto-merge new variables
  from .env.example; validate env for duplicates/broken lines; restart the
  emulator/CMS only when rebuilt or unhealthy; fix step renumbering
- next.config.ts: support NEXT_DIST_DIR for staged production builds
- fix all TS errors (unused imports, missing tryDownloadCandidates helper)
  so tsc and the production build pass clean
- add Dockerfile/.dockerignore and switch docker-compose to a CMS container
- include prevailing UI/refactor changes (SurfaceCard, ticketing, tsconfig)

src/actions/import-furni.ts

@@ -5,20 +5,9 @@ import { db, WebsiteSetting } from "@/lib/db";
 import { PERMS } from "@/lib/permissions";
 import { adminAction } from "@/lib/safe-action";
 import { actionOk } from "@/lib/safe-action-shared";
-import {
-	cleanupConvertedSwfs,
-	deleteImportedItem,
-} from "@/lib/services/furni-import";
+import { deleteImportedItem } from "@/lib/services/furni-import";
 import { siteSettings } from "@/lib/services/site-settings";
 
-export const cleanSwfFiles = adminAction(
-	{ permission: PERMS.ASSETS_IMPORT },
-	async () => {
-		const result = await cleanupConvertedSwfs();
-		return actionOk(result as unknown as Record<string, unknown>);
-	},
-);
-
 const deleteSchema = z.object({ classname: z.string().trim().min(1) });
 
 export const deleteImportedFurni = adminAction(