Studio: read-only packages accept edit gestures client-side, fail only at server write #2259

Mirror of framework#2615 (P1), found by the Studio package-create UX dogfood (framework#2609, audit doc docs/audits/2026-07-studio-package-create-ux-dogfood.md). Reproduced against the pinned console build 7782698 at /_console/studio/com.example.showcase/data (source-loaded, Read-only badge shown).

What happens

On a read-only package:

• "+ Add field" actually mutates the canvas — header count goes 16 → 17 fields and the Field properties panel opens on the new field_17.
• "New object" opens the inline create form and lets the user fill it out.
• "Save draft" / "Publish" remain visible (Publish styled enabled).

Only when the eventual server write fires does the user learn the whole edit was futile — a 422 writable_package_required toast (whose copy is being fixed framework-side in framework#2625).

Expected

Client-side courtesy gating per ADR-0057 D10: when the active package is read-only, disable/hide Add field, New object, Save draft, Publish, and field-property inputs, with a tooltip like "Read-only package — create or switch to a writable package to edit". The server remains the authoritative gate; the client just shouldn't let users build up doomed local state.

Notes

• The read-only signal is already available to the client — the package switcher and Studio landing both badge Read-only correctly.
• Related polish: the read-only toast can fire twice for a single gesture.

🤖 Generated with Claude Code

https://claude.ai/code/session_01DHQc5BdGhTzPfazex3vWdt