[P2] Designer authoring gaps (live prop, no Studio editor) #1895

Part of the metadata liveness audit umbrella #1878 (P2 — cluster #7).

Problem

Designer authoring gaps: a property is live at runtime but has no Studio editor, so it can only be authored by hand-editing JSON.

Checklist

• dataset: filter / format / derived / dateGranularity
• skill: triggerConditions (the activation-critical field)
• flow: notify node (absent from the static palette)

Resolution

All three now have first-class Studio editors:

• dataset filter/format/derived/dateGranularity — ✅ the curated visual dataset designer (DatasetDefaultInspector) covers every prop with a live preview (landed before this pass).
• skill triggerConditions — ✅ array editor (field/operator/value) added to the skill schema-admin form.
• flow notify — ✅ done via feat(studio): first-class notify flow node in the Studio palette + inspector objectui#2808 (merged): notify is now a first-class palette node (Bell icon, Integration group, default-config seed) with a full inspector config editor (recipients/title/message/channels/topic/severity/click-through), mirroring the built-in node's runtime descriptor. Verified by a component-render test (notify-node.dogfood.test.tsx) mounting the real palette + inspector.

All items resolved. Closing.