Allow warning-count in status output to be styled

[rolandwalker]

Description

Allow warning-count in status-footer output to have its own style, output.status.warning-count. Add a warnings.status.warning-count for completeness, though warnings styles remain undocumented for now.

output.status still has a style, and both styles are applied, so if output.status is italic, and output.status.warning-count is red, then the output of the warning count will be red+italic.

A status_plain property is added to SQLResult, since we are still often interested in the plain value, for string matches and calculating width.

Mycli.output now takes a SQLResult rather than a textual status.

A number of tests have to be updated to account for the above two structural changes, and one test assertion on the new style is added.

Example:

This is definitely how I will prefer to consume warning notifications (vs \W), and it is again tempting to change the default.

Checklist

• I added this contribution to the changelog.md file.
• I added my name to the AUTHORS file (or it's already there).
• To lint and format the code, I ran

  uv run ruff check && uv run ruff format && uv run mypy --install-types .

[github-actions]

1. warnings.status.warning-count is currently not applied in warnings output path.
   In mycli/sqlexecute.py:405, warning count is always tagged as class:output.status.warning-count. But warnings rows are printed via MyCli.output(..., is_warnings_style=True), which applies class:warnings.status as the outer style. Result: users cannot target warnings.status.warning-count despite it being added in mycli/clistyle.py:49.
   Action: choose warning-count class based on warning context (or remap in output() when is_warnings_style=True) and add a test covering warnings-mode styling.

2. SQLResult.status is typed as AnyFormattedText, but output() preserves formatting only for FormattedText.
   SQLResult.status now allows any prompt-toolkit formatted text, but main.py:1486-1489 falls back to plain text unless isinstance(status, FormattedText). That strips styles for other valid AnyFormattedText forms (e.g. tuple-lists/HTML), creating a subtle regression risk.
   Action: convert via to_formatted_text(result.status) unconditionally (for non-None) and test at least one non-FormattedText variant.

No direct security issues found in this diff.
I couldn’t run tests locally because pytest/uv are not available in this environment.

[scottnemes]

Verified new formatting for warning count works as expected.