Clear the four style hits that reddened the default branch

The style gate has been failing on main since c8d22f97: a vague opener in gce/aigw.md, two British spellings of license in SKILL.md, and a future tense. All four are the mechanical kind the pipeline configuration says to fix in the docs rather than disable.

A third licence three lines on is fixed too. Vale caught two occurrences and not that one, so grepping the tree beats waiting for the next merge request to surface the rest -- the same pattern as behaviour versus behaviours last week.

No behavior change, docs only. just ci green.