## What
PR 2 of a stacked refactor of the SQL editor snippet state. **Stacked on
#47203 (PR 1)** — review/merge that first.
Extracts scattered business rules + the upsert-payload builder into a
new **pure** module `apps/studio/state/sql-editor/sql-editor-rules.ts`
(no Valtio, React, toast, or runtime data-layer imports):
- `canEditSnippet` — read-only rule (shared snippet you don't own), was
inline in `MonacoEditor` `disableEdit`
- `isSnippetOwner` — owner check, was inline in `ReadOnlyBadge` /
`SavingIndicator`
- `validateMoveToFolder` — 'shared snippet cannot be within a folder',
was a buried `toast.error`
- `buildUpsertPayload` — the PUT /content payload, was an inline object
literal (all `??` defaults preserved)
- `isLoadedSnippet` — type guard (see below)
## Bug fix: no more empty-content saves (and no non-null assertion)
The old payload builder used `{ ...content!, content_id: id }`. Tracing
that `!` upstream surfaced a real bug: **favoriting a snippet from the
sidebar that had never been opened** enqueued a save with no loaded
content, producing a PUT with an empty content body (rejected by API).
The requirement that a persisted snippet has loaded content is now
enforced **at the type level** rather than by a runtime assertion or
comment:
- `buildUpsertPayload` accepts only a `LoadedSnippet` (content
non-nullable) — the `!` is gone.
- the save subscriber crosses that boundary via the `isLoadedSnippet`
type guard.
- the sidebar favorite toggle loads content first (mirroring
`onSelectDuplicate` / the share modals), narrowing the fetched union
content to the SQL variant via its discriminant — **no type cast**.
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **Bug Fixes**
* Improved consistency in read-only behavior and ownership checks across
the SQL editor by centralizing permission logic.
* Fixed favorite toggle to ensure snippet content is fully loaded before
persisting changes.
* **Refactor**
* Centralized SQL snippet permission rules and validation logic into a
dedicated helper module.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
