feat(executiontime): add ISO 8601 duration format

[dohzya]

Prerequisites

• I have read and understood the contributing guide.
• The commit message follows the conventional commits guidelines.
• Tests for the changes have been added (for bug fixes / features).
• Docs have been added/updated (for bug fixes / features).

Description

Adds two new duration styles for the executiontime segment using the ISO 8601 duration format:

• iso8601: Displays time with second precision (e.g., PT3M2S)
• iso8601ms: Displays time with millisecond precision (e.g., PT3M2.1S)

This follows the same pattern as existing formats like galveston and galvestonms.

Format Examples

Duration	iso8601	iso8601ms
0.001s	PT0S	PT0.001S
2.1s	PT2S	PT2.1S
3m2.1s	PT3M2S	PT3M2.1S
4h3m2.1s	PT4H3M2S	PT4H3M2.1S

Test Plan

• Added unit tests for both formats (24 test cases total)
• All tests pass (17/17 executiontime tests)
• Documentation updated with examples

Configuration Example

{
  "type": "executiontime",
  "options": {
    "style": "iso8601",
    "threshold": 500
  }
}

🤖 Generated with Claude Code

[dohzya]

Hi @JanDeDobbeleer 👋

Just to be clear: this isn't some random AI-generated contribution—it's a genuine feature I need and wanted to propose instead of just requesting." 🙂

I currently use a custom template to achieve this goal, but I figure I can't be the only one with this need.

Here is my current template:

{{- $ms := .Ms -}}
{{- if le $ms 0 -}}
{{- /* rien */ -}}
{{- else -}}
{{- $sTotal := div $ms 1000 -}}
{{- $h := div $sTotal 3600 -}}
{{- $m := div (mod $sTotal 3600) 60 -}}
{{- $s := mod $sTotal 60 -}}
PT{{- if gt $h 0 -}}{{ $h }}H{{- end -}}
{{- if gt $m 0 -}}{{ $m }}M{{- end -}}
{{- $s -}}S
{{- end -}}

[JanDeDobbeleer]

@dohzya question though, what's the use-case here for executiontime? Is it really running long enough to have a need for this format?

[dohzya]

Oh, I prefer this format whatever the duration, and other formats also support up to hours 🙂

Yes, sessions of vim or claude-code can take hours, even days. For instance, I tend to put my work laptop to hibernation instead of shutting it down during the weekend, without stopping my claude-code sessions first.

I followed what other formats do by sticking to PT<time> (I suppose because longer durations can't be calculated from the milliseconds-based representation, notably due to leap seconds).

[JanDeDobbeleer]

@all-contributors please add @dohzya for code,doc

This is pure magic 🪄! @holopin-bot @dohzya wizard

[holopin-bot]

Congratulations @dohzya, the maintainer of this repository has issued you a badge! Here it is: https://holopin.io/claim/cmmrj6rue0001jp04761c0kmf

This badge can only be claimed by you, so make sure that your GitHub account is linked to your Holopin account. You can manage those preferences here: https://holopin.io/account.
Or if you're new to Holopin, you can simply sign up with GitHub, which will do the trick!

[allcontributors]

@JanDeDobbeleer

I've put up a pull request to add @dohzya! 🎉