feat(image): complete reviewed generation delivery

mindspace-workspace-thumbnails.mjs

@@ -4,6 +4,16 @@ import path from 'node:path';
 import { ensureThumbnailPng } from './mindspace-thumbnail-png.mjs';
 import { ensureHtmlThumbnail } from './mindspace-thumbnails.mjs';
 
+function reportSidecarFailure(kind, htmlRelativePath, error) {
+  // A page can be removed immediately after a fire-and-forget publish event.
+  // That is a normal cancellation, not a thumbnail generation failure.
+  if (error?.code === 'ENOENT') return;
+  console.warn(
+    `[MindSpaceThumbnail] ${kind} failed for ${htmlRelativePath}:`,
+    error instanceof Error ? error.message : error,
+  );
+}
+
 export function workspaceThumbnailRelativePath(htmlRelativePath) {
   const normalized = String(htmlRelativePath ?? '').replace(/^\/+/, '');
   const dir = path.posix.dirname(normalized);
@@ -23,14 +33,15 @@ function scheduleWorkspaceThumbnailPng(publishDir, htmlRelativePath) {
         const svgPath = workspaceThumbnailAbsolutePath(publishDir, htmlRelativePath);
         if (fs.existsSync(svgPath)) ensureThumbnailPng(svgPath);
       })
-      .catch(() => {});
+      .catch((error) => reportSidecarFailure('PNG sidecar', htmlRelativePath, error));
   });
 }
 
 /** Fire-and-forget SVG + PNG sidecars after public HTML is written (must not block Finish/chat). */
 export function scheduleWorkspaceHtmlThumbnailSidecars(publishDir, htmlRelativePath) {
   queueMicrotask(() => {
-    void ensureWorkspaceHtmlThumbnail(publishDir, htmlRelativePath).catch(() => {});
+    void ensureWorkspaceHtmlThumbnail(publishDir, htmlRelativePath).catch((error) =>
+      reportSidecarFailure('sidecar refresh', htmlRelativePath, error));
   });
 }