feat: Add support for transaction status indicator (\T) in prompt

[devadathanmb]

Description

Adds support for displaying transaction status in the prompt via the \T escape sequence, similar to psql's %x

Behavior:

• * — inside a valid transaction block
• ! — inside a failed transaction block
• ? — connection is closed/indeterminate
• (empty) — idle, not in a transaction

Example usage in ~/.config/pgcli/config:

prompt = '\u@\h:\d>\T '

This produces prompts like (as shown in the attached screenshot below):

user@localhost:mydb>  SELECT 1;      -- idle

user@localhost:mydb>* BEGIN;         -- in transaction

user@localhost:mydb>! ...            -- failed transaction

user@localhost:mydb>? ...            -- if connection is closed

NOTE: Uses \T instead of \x to avoid conflicts with ANSI escape sequences (\x1b) processing done in the codebase.

Closes #1552

Checklist

• I've added this contribution to the changelog.rst.
• I've added my name to the AUTHORS file (or it's already there).

• I installed pre-commit hooks (pip install pre-commit && pre-commit install).
• Please squash merge this pull request (uncheck if you'd like us to merge as multiple commits)

[Copilot]

Pull request overview

This PR adds support for a transaction status indicator escape (\T) in the prompt, analogous to psql’s %x, so users can see transaction state directly in their prompt.

Changes:

• Introduces PGExecute.transaction_indicator (and is_connection_closed) to derive a single-character transaction state marker (*, !, ?, or empty).
• Extends PGCli.get_prompt and the default pgclirc configuration to support a new \T prompt escape for transaction status.
• Adds tests for \T prompt rendering and updates AUTHORS.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
pgcli/pgexecute.py	Adds is_connection_closed and the transaction_indicator property, reusing existing transaction status helpers to compute the * / ! / ? / empty marker.
pgcli/main.py	Extends get_prompt to replace \T with pgexecute.transaction_indicator, wiring the new indicator into prompt rendering.
pgcli/pgclirc	Documents the new \T prompt escape and its behavior alongside existing prompt placeholders.
tests/test_main.py	Adds tests covering \T in simple and full prompts; currently sets transaction_indicator via PropertyMock on MagicMock’s type, which mutates global MagicMock state.
AUTHORS	Adds a new contributor entry.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[devadathanmb]

I’m not sure why this test is failing. It doesn’t appear to be related to the changes in this patch.

The same patch passes all CI checks on my fork (see: https://github.com/devadathanmb/pgcli/actions/runs/21539731264?pr=2)

Could you please rerun the actions?