Fix OA workspace cover thumbnails and add space chat new session.

Resolve mindspace-cover images from workspace directories when generating feed thumbnails, refresh stale SVGs missing embedded photos, and disable thumbnail API caching so fixes take effect immediately. Also add a new session control to the space chat panel, including on mobile.

Co-authored-by: Cursor <cursoragent@cursor.com>

mindspace-thumbnails.mjs

@@ -451,6 +451,30 @@ export function isModernFeedThumbnail(svg) {
   return /width="540" height="720"/.test(svg) && /filter id="grain"/.test(svg);
 }
 
+export function thumbnailHasEmbeddedPhoto(svg) {
+  return /href="data:image\//.test(String(svg ?? ''));
+}
+
+export function resolveWorkspaceHtmlContentBaseDir(workspacePublishDir, workspaceHtmlRelativePath) {
+  if (!workspacePublishDir || !workspaceHtmlRelativePath) return undefined;
+  const dir = path.posix.dirname(String(workspaceHtmlRelativePath).replace(/^\/+/, ''));
+  return dir === '.' ? workspacePublishDir : path.join(workspacePublishDir, dir);
+}
+
+async function shouldRegenerateThumbnailForCover(storageRoot, html, meta, existing) {
+  if (!existing || !isModernFeedThumbnail(existing) || meta.force) return Boolean(meta.force);
+  const signals = extractCoverSignals(html, meta);
+  if (!signals.image) return false;
+  if (thumbnailHasEmbeddedPhoto(existing)) return false;
+  const coverDataUri = await resolveCoverDataUri({
+    storageRoot,
+    contentStorageKey: meta.contentStorageKey,
+    contentBaseDir: meta.contentBaseDir,
+    imageUrl: signals.image,
+  });
+  return Boolean(coverDataUri);
+}
+
 export async function generateHtmlThumbnail(storageRoot, storageKey, html, meta = {}) {
   const signals = extractCoverSignals(html, meta);
   const coverDataUri = await resolveCoverDataUri({
@@ -467,7 +491,13 @@ export async function generateHtmlThumbnail(storageRoot, storageKey, html, meta
 export async function ensureHtmlThumbnail(storageRoot, storageKey, html, meta = {}) {
   const existing = await readThumbnailIfExists(storageRoot, storageKey);
   if (existing && isModernFeedThumbnail(existing) && !meta.force) {
-    return existing;
+    const needsCoverRefresh = await shouldRegenerateThumbnailForCover(
+      storageRoot,
+      html,
+      meta,
+      existing,
+    );
+    if (!needsCoverRefresh) return existing;
   }
   return generateHtmlThumbnail(storageRoot, storageKey, html, meta);
 }
@@ -480,17 +510,34 @@ export async function ensurePageThumbnail({
   workspacePublishDir = null,
   workspaceHtmlRelativePath = null,
 }) {
+  const contentBaseDir =
+    meta.contentBaseDir ??
+    resolveWorkspaceHtmlContentBaseDir(workspacePublishDir, workspaceHtmlRelativePath);
+  const enrichedMeta = contentBaseDir ? { ...meta, contentBaseDir } : meta;
+
   if (workspacePublishDir && workspaceHtmlRelativePath) {
     const sidecar = await readThumbnailIfExists(
       workspacePublishDir,
       workspaceThumbnailRelativePath(workspaceHtmlRelativePath),
     );
     if (sidecar && isModernFeedThumbnail(sidecar)) {
-      await writeThumbnail(storageRoot, pageThumbnailStorageKey, sidecar);
-      return sidecar;
+      if (thumbnailHasEmbeddedPhoto(sidecar)) {
+        await writeThumbnail(storageRoot, pageThumbnailStorageKey, sidecar);
+        return sidecar;
+      }
+      const needsCoverRefresh = await shouldRegenerateThumbnailForCover(
+        workspacePublishDir,
+        html,
+        enrichedMeta,
+        sidecar,
+      );
+      if (!needsCoverRefresh) {
+        await writeThumbnail(storageRoot, pageThumbnailStorageKey, sidecar);
+        return sidecar;
+      }
     }
   }
-  return ensureHtmlThumbnail(storageRoot, pageThumbnailStorageKey, html, meta);
+  return ensureHtmlThumbnail(storageRoot, pageThumbnailStorageKey, html, enrichedMeta);
 }
 
 export async function readThumbnailIfExists(storageRoot, storageKey) {