The canvas.html body contained <rstack-tab-bar>, <rstack-space-settings>,
and <rstack-history-panel> elements that weren't being stripped by
extractCanvasContent (the tab-row regex failed due to extra children).
When injected via TabCache, these duplicate elements interfered with the
shell's tab management, causing tabs to appear wiped.
Fixes:
- Server: robust div-counting strip for rstack-tab-row + explicit strips
for space-settings and history-panel
- Client: DOM-based safety strip in TabCache.extractContent()
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Jeff Emmett
e8379541cc