* feat(agents): create agent registry and service
* fix: mark agent offline only if the session was removed properly
* refactor: centralize agent backup lifecycle state
* refactor: simplify session management
* refactor: move effect / async boundary in one place
* chore: regen migration
* refactor: improve error handling
* chore: pr feedback
* feat(agent): add standalone agent runtime
* fix(backups): bridge local executor to Effect restic API
* fix(agent): add Bun and DOM types to agent tsconfig
* refactor: wrap backup error in a tagged effect error
* fix: pr feedbacks