When SaveSnapshot receives an image tensor, extract a 200x150 JPEG
thumbnail (base64) and include it in the snapshot record. Sidebar shows
a small preview, tooltip displays the generated image instead of SVG,
and the preview modal shows the image above the graph.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Introduce a SaveSnapshot custom node that triggers snapshot captures
via WebSocket. Node-triggered snapshots are visually distinct in the
sidebar (purple left border + "Node" badge) and managed with their
own independent rolling limit (maxNodeSnapshots setting), separate
from auto/manual snapshot pruning. Node snapshots skip hash-dedup
so repeated queue runs always capture.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
