* feat(custom-block): move management to enterprise settings; derive inputs live from deployed start
* fix(custom-block): key custom-blocks query by workspaceId (react-query audit)
* fix(custom-block): restore icon on discard instead of clearing the saved image
* fix(custom-block): track create-flow dirty state and reset selections on discard
* fix(custom-block): merge placeholders for id-less start fields; compare inputs by authored data only
* improvement(custom-block): dedup input-mapping helper, reuse SettingsResourceRow + shared reserved-param set
* fix(custom-block): keep disabled blocks resolvable so placed instances fail loudly instead of vanishing
* fix(custom-block): derive fields for disabled blocks so edits keep placeholders; reseed edit form after async load
* fix(custom-block): scope publish workspace picker to the current org