## I have read the
[CONTRIBUTING.md](<https://github.com/supabase/supabase/blob/master/CONTRIBUTING.md>)
file.
YES
## What kind of change does this PR introduce?
Bug fix for Studio notebook previews.
## What is the current behavior?
Notebook diffs display the raw database_identifier value. This exposes
opaque database IDs and does not communicate whether the cell targets
the primary database or a read replica.
Related issue:
[https://linear.app/supabase/issue/FE-4246](<https://linear.app/supabase/issue/FE-4246>)
## What is the new behavior?
Notebook database metadata is resolved independently from existing
selector formatting:
* an omitted database identifier is Primary
* an identifier matching the project ref is Primary
* other identifiers show a loading state while databases load
* a loaded non-primary match is Replica
* an unmatched identifier is Unknown
* database lookup failures use a neutral unavailable state
Labels are compact: Database: Primary, Database: Replica, and Database:
Unknown.
The databases query is enabled only when a preview contains an explicit
non-primary identifier.
## Additional context
Validation:
* 39 focused notebook preview tests
* Studio typecheck
* targeted ESLint
* Prettier check
* git diff --check
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Notebook previews now identify database targets as primary, read
replica, or unknown.
* Database metadata is resolved automatically when needed.
* Loading states display a clear “Loading database…” indicator.
* Database metadata now handles unavailable, hidden, and error states
more clearly.
* Notebook entries reflect updated database information before and after
replacement.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## Summary
- Reverts #49326's temporary mitigation, which stripped
`database_identifier` from the agent-facing notebook cell schema
(`agentCellSchema`) because the assistant had no legitimate source of
truth for valid read-replica identifiers.
- The previous PR in this stack (#49328) added the `list_databases`
tool, so that source of truth now exists — `database_cell`s can carry
`database_identifier` again.
Part 3/6 of the stack for FE-4225 (expose valid database identifiers to
the notebook AI agent). Stacked on #49328.
## Test plan
- [x] Existing schema/preview tests (reverted alongside the mitigation)
pass
- [x] `pnpm --filter studio exec tsc --noEmit` passes
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* AI-generated notebook database cells now support database identifiers.
* Notebook previews display the associated database source, including
transitions between primary and replica databases.
* **Bug Fixes**
* Improved database metadata handling to preserve identifiers when
updating notebook cells.
* Database information is now shown only when available, preventing
inaccurate or missing metadata displays.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## Summary
- The AI assistant's `create_notebook`/`update_notebook` tools could set
a `database_cell`'s `database_identifier` to a value that doesn't
correspond to any real database, because no tool exposes a project's
actual read-replica identifiers to the model.
- An unresolvable `database_identifier` silently breaks the cell:
`QueryEditor`'s connection-string lookup fails to find a match, and
running the cell fails with `Unable to run query: Connection string is
missing` — even though the exact same SQL runs fine when pasted into a
manually-created cell (which never sets this field).
- Fix: strip `database_identifier` from the agent-facing schema
(`agentCellSchema` in `notebook-schema.ts`) entirely, so the model can
no longer emit it at all. **This is a temporary fix** until we wire in
real read-replica support for the AI assistant (e.g. a tool exposing a
project's valid replica identifiers) — the field can be reintroduced
once the model has a legitimate source of truth to pull a valid
identifier from.
- Updated tests that relied on agent cells carrying
`database_identifier` to reflect the new behavior, and added a
regression test asserting `agentNotebookSchema` rejects a
`database_cell` with that field set.
Resolves FE-4224
## Test plan
- [x] `notebook-schema.test.ts`, `notebook-operations.test.ts`,
`notebook-tools.test.ts`, `AssistantNotebookPreview.test.tsx`,
`AssistantNotebookPreview.utils.test.ts` all pass
- [x] `tsc --noEmit` clean
- [x] Prettier clean on touched files
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **Bug Fixes**
* Improved handling of database notebook cells when database metadata is
unavailable.
* Cells without database identifiers now display “No metadata” instead
of an incorrect replica identifier.
* Prevented invalid database identifiers from being accepted in
agent-generated notebook content.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
<img width="840" height="507" alt="image"
src="https://github.com/user-attachments/assets/d0f4667f-a7bb-4afe-95b2-a9e224adcbb5"
/>
<img width="848" height="597" alt="image"
src="https://github.com/user-attachments/assets/beb0c239-d36c-4103-ab07-8a3872ba3f30"
/>
Updates how we display Notebooks in Assistant to be more in line with
our AssistantQueryCell.
## To test:
- Open Assistant and ask it to create a test notebook and note the new
styling
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Added unified, read-only notebook previews for create and update
proposals.
* Preview cells now support expandable content, clearer type icons,
metadata, and “Show more” controls.
* Added before-and-after metadata comparisons for replaced cells.
* Integrated previews into confirmation cards with approval, skip, and
refresh actions.
* Added skip-only confirmation flows when approval is unavailable.
* **Bug Fixes**
* Improved handling of parse failures, stale notebooks, invalid changes,
and loading errors.
* **Style**
* Refined confirmation card layouts, borders, spacing, and footer
presentation.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
Charis