## Context
Related to database connections - specifically for cancelling queries or
terminating sessions
PIDs can be re-used, so a more accurate check is to use both PID and
`backend_start` to uniquely identify the session to cancel or terminate
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
* **Bug Fixes**
* Improved query cancellation and session termination reliability by
verifying the active database session before taking action.
* Prevented actions from affecting a different session that reused the
same process ID.
* Added clearer guidance to refresh when a session has changed or is no
longer available.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
## Context
Initial work for Top for Postgres - adds a "Sessions" section under a
new Observability segment "Database Connections"
NOTE: All the copywriting and naming might change - not sure what's an
ideal title for this
We'll also be iteratively building on top of this UI, adding more
actionable signals instead of just information
Changes are featured flagged, off for public
- This would essentially replace the "View ongoing queries" in the SQL
Editor by providing a dedicated UI
- It checks against `pg_stat_activity` as per the ongoing queries UI
- We'll also subsequently deprecate the "Ongoing queries" UI in the SQL
editor
- Defaults into a "live mode" where the data is refreshed every 3
seconds via long-polling
<img width="983" height="474" alt="image"
src="https://github.com/user-attachments/assets/16402fe4-0b53-4f9e-9342-cdda26e3778a"
/>
- Supports filtering by state
<img width="374" height="282" alt="image"
src="https://github.com/user-attachments/assets/562f8fbe-2dc6-48e7-8ec0-de7ffb8348d1"
/>
- Users can also terminate queries through here
<img width="247" height="164" alt="image"
src="https://github.com/user-attachments/assets/23a639dc-8f96-473a-a823-605b0bab02ee"
/>
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit
# Release Notes
* **New Features**
* Added an Observability **Database Connections** page with a live
**Sessions** activity table (state/roles filtering, blocked-by details,
session duration, and per-session termination with confirmation).
* Included a **Live/Pause** toggle to control automatic refresh (~3
seconds).
* **Enhancements**
* Improved Reports selection filtering: supports optional option
quantities, better popover styling, sorted apply behavior, and shows
quantity inline.
* Query performance duration formatting now supports configurable
decimal precision.
* Tooltips can now render richer content (string or React node).
<!-- end of auto-generated comment: release notes by coderabbit.ai -->
