Ship default C-Suite roster with NixOS module

Ship a default C-Suite roster (32 agents) so that agent-roster.enable = true provisions all agents out of the box.

Changes

• 7 C-Suite officers (maintainer access)
• 2 Executive assistants to CEO (developer access)
• 13 Department heads (developer access)
• 10 Specialist roles (developer access, needypants as reporter)
• Working directory constraint updated to home directory
• mkAgent helper for DRY agent definitions
• defaultRoster set as default for agents option

Agents added in latest push

• snappypants (Executive Assistant to CEO)
• fussypants (Executive Assistant to CEO)
• grumpypants (Project Manager)
• trashypants (Deprecation Engineer)
• scrappypants (Prototype Engineer)
• craftypants (Solutions Architect)
• snippypants (Internal Maintenance Engineer)