## Context
As per PR title - this behaviour currently exists in the SQL Editor so
just bringing it over to the Explorer, applies to both QueryTab and
QueryCell since they use the same QueryEditor component
"Run" button also updates to "Run selected" for clarity when a specific
portion of the code editor is selected
<img width="1387" height="958" alt="image"
src="https://github.com/user-attachments/assets/7e652951-3c07-4f8d-851b-bb9219d0c1f2"
/>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit
* **New Features**
* Run only the selected SQL when text is highlighted in the query
editor.
* Run the full query when no text is selected.
* Updated the run button label and tooltip to reflect the action.
* **Bug Fixes**
* Improved query execution for empty or collapsed selections.
* Corrected selection state when reopening the query editor.
* **Tests**
* Added coverage for selected-text, full-query, and editor reopening
scenarios.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
