Commit summary length hints (warning at 50, error at 72)

**Is your feature request related to a problem? Please describe.**
The waning coloring on the commit message is quite restrictive. Especially when company want to tag some commits with the issue ID it resolve, if the commit is a `feat`ure, a `fix`, … or sometime the `[functionality]` impacted. Real world software (screen size, website view, …) are more tolerant on long sized summary. Learning materials I read are more permissive than this 50 char "rule", ex in https://cbea.ms/git-commit/#limit-50 they say:
> So shoot for 50 characters, but consider 72 the hard limit.

Even in the linux kernel some message may be very long https://stackoverflow.com/a/11993051.

**Describe the solution you'd like**
When writing the summary, a warning color (yellow/orange) appear at 50 glyph, this transform in an error (current red is good) wean reaching 72 glyphs.
I really like to have a warning when I arrive at 50, I see if I should rephrase it now or not. When reaching 72 I take a bit more time to shorten my summary (and sometimes expand the body).

**Describe alternatives you've considered**
Keeping things as is since the real message is not limited in size. Or having configurable values.

No files or tests are named in the issue. Start by locating the commit-summary length validation and its UI entry point, then inspect how the current warning color and 50-character limit are applied. Done means summaries warn at 50 glyphs, use the existing error styling at 72, and retain the requested behavior for longer text.

Vom Indexierungsmodell aus dem Issue-Text verfasst.