fix(trail): flag onboarding-created runners left un-tailored

Onboarding writes the default runner set, then tune tailors in place. If a runner's tailoring is skipped, omitted by the model, or returned verbatim, it stays a generic default — and the previous "Updated N… review with git diff" nudged the user to commit those generic placeholders as if they were repo-specific.

ensureRunnersPresent now reports which runners it created; applyTuneWithAgent tracks which were actually tailored and warns about any created-but-untailored ("…still generic defaults, not tailored to this repo: …; re-run or edit/remove before committing"). The --print path likewise notes that freshly-created defaults are untracked and not yet tailored.