Merges the skill half of the persona/skill pair plus the second nested module.
(Squashed onto main from phase-4b-skill; the audit/budget/persona batteries it
was stacked on already landed via the P4 merge.)
- skill/: clean-redesign Skill noun + LEAN SkillStore (lifecycle/versions/
schedule only) + ToRunnable + Memory default.
- contrib/store/: separate go.mod carrying modernc.org/sqlite, so the driver
never enters the core go.sum. db.Budget()/Personas()/Skills()/Audit() back
all four store seams (JSON-blob + indexed columns; round-trip tested).
Includes the verified gadfly #5 fixes (AppendVersion tx+UNIQUE+error,
Mark*ScheduledRun atomic json_set, busy_timeout, NaN guard).
- CI: builds + tests the nested module and asserts it owns the sqlite driver.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
