## Description
Adds a PostgreSQL tool kind `postgres-list-active-queries` that returns
the top N currently running queries (`state='active'`) from
`pg_stat_activity`, ordered by longest running first. Each row includes:
`pid`, `user`, `database`, `application_name`, `client_addr`, `state`,
`wait_event_type`, `wait_event`, `backend_start`, `xact_start`,
`query_start`, computed `duration`, and `query` (SQL text).
Parameters supported
- `min_duration` (optional) — only include queries running at least this
long (e.g., "1 minute", "2 seconds").
- `exclude_application_names`(optional) — comma-separated list of
application_name values to exclude (e.g., "psql,pgAdmin 4,my-batch").
- `limit` (optional) — max rows to return (default 50).
**Test Output**
- Test without filter:
<img width="1439" height="894" alt="image"
src="https://github.com/user-attachments/assets/92009211-4f71-4830-a689-4fd2f0558477"
/>
- Test with filter, but response
<img width="1451" height="893" alt="image"
src="https://github.com/user-attachments/assets/903a0fc4-ad3e-4e9f-aacd-0b6349addc94"
/>
- Test with filter, but no response
<img width="1411" height="896" alt="image"
src="https://github.com/user-attachments/assets/a4d74883-11cc-402f-abcf-cd998e247209"
/>
---
> Should include a concise description of the changes (bug or feature),
it's
> impact, along with a summary of the solution
## PR Checklist
---
> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:
- [x] Make sure you reviewed
[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [x] Make sure to open an issue as a
[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
before writing your code! That way we can discuss the change, evaluate
designs, and agree on the general idea
- [x] Ensure the tests and linter pass
- [x] Code coverage does not decrease (if any source code was changed)
- [x] Appropriate docs were updated (if necessary)
- [x] Make sure to add `!` if this involve a breaking change
Co-authored-by: Yuan Teoh <45984206+Yuan325@users.noreply.github.com>