[Bug] `taskLog` does not correctly handle carriage-return spinner/progress output

[colinaaa]

Environment

• OS: All
• Node Version: v24.14.1
• Package: @clack/prompts
• Package Version: v1.2.0

Describe the bug

taskLog does not correctly handle carriage-return (\r) updates from spinner/progress-style output.
When a tool writes multiple updates to the same terminal line using carriage returns, taskLog does not model those updates as in-place overwrites. As a result, intermediate frames can accumulate in the internal log state and the rendered output/clearing behavior can become inconsistent on completion, especially around error() and showLog.
This seems related to taskLog being a raw prompt with its own rendering logic instead of using the shared rendering path used by other prompts.

To Reproduce

Steps to reproduce the behavior:

• Create a taskLog instance from @clack/prompts
• Stream spinner-like updates with carriage returns, for example:

  import * as prompts from '@clack/prompts';
  const log = prompts.taskLog({
  	title: 'foo',
  });
  log.message('◒  Cloning repository', { raw: true });
  log.message('\r◐  Cloning repository', { raw: true });
  log.message('\r◓  Cloning repository', { raw: true });

Expected behavior

taskLog should treat carriage-return updates as overwrites of the current visible line.
That means:

• only the latest spinner/progress frame should be retained
• intermediate frames should not accumulate in the log
• error() / success() rendering should reflect the final visible state
• clearing behavior should match the number of actually rendered lines

Additional Information

See: #509 (comment)

[43081j]

for maintainers: once we move the spinner to be a Prompt, we should do the same with the task log.

it'd be good to fix this as part of that