Connecting the last image slot appends a fresh empty one, so a chain can be extended
without pressing a button. Its sibling RMMakeImageBatch uses an explicit "Add Image
Input" button; here slot order IS chain order, so the next slot should already be waiting.
Only the tail is managed - there is always exactly one trailing empty slot. Middle gaps
are deliberately left alone: the Python side sorts by slot number and skips unwired slots,
so 1,3,4 is still the chain 1->3->4, and compacting would silently re-point every parent
link in the lineage record.
Slot bookkeeping is deferred a frame and made idempotent, because LiteGraph fires
onConnectionsChange once per restored link during a workflow load - it must converge
rather than accumulate slots.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012uM7Ru1JYn48n6c5Rzwd99
