## Summary
A round of small Explorer refinements.
**Sidebar**
- Adds a **Run SQL** row (with a `+` icon) above Notebooks in the
Explorer sidebar; opens a new query tab.
**Assistant**
- Assistant query cells now have the same **Save** dropdown as query
tabs (add to an existing notebook or create a new one). It shows only
when Explorer is enabled, and not while the query is still streaming.
- `SaveQueryDropdown` takes an optional `source`, so logs queries are
saved as log cells (keeping their time range) instead of database cells.
This also fixes saving logs queries from query tabs.
- The "Drafting notebook..." notice (and the notebook loading/status
rows) now span the full message width; `delete_notebook` parts use the
wide layout like create/update.
**Onboarding**
- Replaces the single page with a four-step walkthrough: Welcome to
Explorer (with a **Preview** badge), Run SQL, Notebooks, and Chat with
your project. Each step has an icon, heading, and short description,
with step dots and **Skip** / **Back** / **Next** buttons; the last step
ends with **Continue to Explorer**.
- Removes the "Choose how Explorer opens" choice (still available in
Account preferences) and the collapsible "Learn more" section. Skipping
or finishing still respects the saved startup preference.
- Deletes `ExplorerOnboardingLearnMore`, `ExplorerHomePreference`, and
`ExplorerHomePreview`, which were only used by onboarding.
**Notebooks**
- Query cells use the same max width as markdown cells (`48rem`, was
`72rem`).
- "Add query cell" / "Add markdown cell" are now **Add query** / **Add
markdown** everywhere; the buttons at the bottom of a notebook are
larger (34px, 18px icons).
## Test plan
- [ ] Explorer sidebar: **Run SQL** opens a new query tab
- [ ] Assistant: generate SQL, use **Save** to add it to a new and an
existing notebook; repeat with a logs query and confirm a log cell is
created
- [ ] Assistant: ask for a notebook and confirm the drafting notice is
full width
- [ ] Clear `hasCompletedOnboarding` in Explorer preferences and step
through onboarding (Next / Back / Skip); finishing or skipping respects
the startup preference set in Account preferences
- [ ] Notebook: query cells line up with markdown cell width; bottom add
buttons are larger
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
- **New Features**
- Added a **Run SQL** shortcut to Explorer navigation.
- Assistant query results can now be saved to notebooks, including log
queries.
- **Improvements**
- Updated Explorer onboarding with guided steps, progress navigation,
and visual previews.
- Shortened Explorer action labels and refined control sizing.
- Reduced notebook query layout width and adjusted assistant notebook
displays.
- **Changes**
- Removed the Explorer startup preference selector and onboarding “Learn
more” section.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
---------
Co-authored-by: Claude Opus 5 <noreply@anthropic.com>
## Context
Related to Explorer/Notebooks - this PR adds the functionality to add /
remove cells
Separately - am thinking we can shift a lot of the "cell update" logic
into notebook-state, mainly so that each UI component doesn't need to be
aware of the notebook's `cells` but just its own cell.
I'll do it separately though to prevent bloating this PR, already left
comments where i think can be refactored
<img width="250" alt="image"
src="https://github.com/user-attachments/assets/91aae5f9-07b9-4327-8e21-8e9d71098aa6"
/>
<img width="250" alt="image"
src="https://github.com/user-attachments/assets/677de208-5c52-4155-90c6-bc0879070693"
/>
<img width="250" alt="image"
src="https://github.com/user-attachments/assets/17c3dae7-87bc-40bb-bfa0-15df101006ce"
/>
<img width="1091" height="262" alt="image"
src="https://github.com/user-attachments/assets/a09c3d23-696a-4b55-a1f8-4602e56a60dc"
/>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
## New Features
- Add query and Markdown cells directly within notebooks.
- Move, remove, and reorder cells using drag-and-drop or cell controls.
- Add cells from empty states and notebook toolbar actions.
- Edit Markdown cells, mark edits as complete, and see placeholders for
empty content.
## Improvements
- Cell controls and hover interactions are more consistent and
responsive.
- Moving cells is disabled at the top or bottom of a notebook.
- Sample cells now use standardized content and formatting.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
