feat(skills): add commit workflow, explain and help-skills

comments-clean purges explanatory comments before every operator-requested stage or commit and penalizes own violations into persistent memory; commit-no-verify commits the exact staging index with hooks skipped, the invocation itself being the per-commit authorization; commit-next chains both and stages the next logical bundle with an explain and confidence briefing; explain walks code and its collaborators in execution order and offers a Mermaid schema in the affected README; help-skills lists every project, global and plugin skill with triggers and composition.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

skills/commit-next/SKILL.md

@@ -0,0 +1,20 @@
+---
+name: commit-next
+description: >
+  Commit the staged bundle with --no-verify, then stage the next logical
+  bundle and brief the operator on it. Trigger on /commit-next or when the
+  operator asks to commit and stage the next bundle in one step. Portable
+  across projects.
+---
+
+1. Run the commit-no-verify skill on the currently staged changes
+   (comments-clean audit first, then `git commit --no-verify`, exact
+   staging index only).
+2. Group the remaining uncommitted changes into logical bundles (one
+   concern per bundle: same failure class, same mechanism, or same role)
+   and stage the next one; never mix concerns to save a commit.
+3. For the newly staged bundle run the explain skill (what the changes do
+   and how the pieces interact, file:line-anchored) followed by the
+   confidence skill (fix confidence, break risk, evidence, residuals).
+4. Close with what remains unstaged and wait for the operator's commit
+   decision; never auto-commit the newly staged bundle.