chore: add activity-coverage dimension to gap-analysis skill (#744)

* chore: add activity-coverage dimension to gap-analysis skill

Adds a sixth audit dimension (and an `activities` invocation scope) that
diffs which of the 7 core activity kinds each provider ships an adapter
for against what upstream offers, with a provider×activity grid in the
report template.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* ci: apply automated fixes

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Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

Author: 3 people