Fixed "couldnt find ketcher instance N" error when clicking OK on the cell editor dialog: the change handler now bails out if the sketcher is detached while a getMolfile() call is still in flight
Hid Extended Table generic-atom buttons that can't be translated to RDKit-compatible V2000 query features from the substructure filter sketcher only — full set remains available in other sketcher contexts.
Deferred Ketcher's React Editor mount until ketcher-host has non-zero dimensions (ResizeObserver-gated) so RulerArea can resolve the canvas SVG's relative-unit sizes on its first render — adopted from PR #3789 (CLAUDE-159)
Fixed structure filter not clearing when the filter-panel "clear" is hit while the sketcher is detached: _setNotation now zeroes the cached notations and resets molfiles to whitespace molblocks when called with an empty value on a detached sketcher