Add `mosaic fleet provision --profile <id> [--full] [--write] [--force]`: materialize a concrete, parser-valid roster.yaml from a declared system-type profile. DRY-RUN by default (prints roster + topology, writes nothing); --write persists under <mosaicHome>/fleet/roster.yaml and refuses to clobber without --force. Reuses loadProfile/validateProfile (fleet-profiles) and resolvePersona (fleet-personas, override-aware); generation policy is local + documented. Co-Authored-By: Claude Opus 4.8 <[email protected]>