fix(dashboard): reload on stale chunk after redeploy

Builds now emit version.json + a __BUILD_VERSION__ define. The client
re-checks the remote version on visibilitychange/focus and reloads on
mismatch, so a backgrounded tab doesn't hit a 404'd hashed chunk and
surface "'text/html' is not a valid JavaScript MIME type" when opening
Settings. ErrorBoundary catches stale-chunk errors as a safety net.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/dashboard/app/components/ErrorBoundary.tsx

@@ -1,5 +1,6 @@
 import { Component, type ReactNode, type ErrorInfo } from "react";
 import { AlertTriangle } from "lucide-react";
+import { handleChunkLoadError } from "../versionCheck";
 import "./ErrorBoundary.css";
 
 interface ErrorBoundaryProps {
@@ -26,6 +27,7 @@ export class ErrorBoundary extends Component<ErrorBoundaryProps, ErrorBoundarySt
 
   componentDidCatch(error: Error, errorInfo: ErrorInfo): void {
     console.error("[ErrorBoundary]", error, errorInfo);
+    if (handleChunkLoadError(error)) return;
     this.props.onError?.(error, errorInfo);
   }