Provisioning: Migrate `bootstrap`, implement `make reset`

[khvn26]

Parent epic

Part of #6797

Blocked by

• Provisioning: Implement the API #6799 (Phase 1: core engine and management command)

Summary

Replace the existing bootstrap management command and make reset flow with the new provisioning system.

Scope

bootstrap → thin wrapper around provision

• Create a default bootstrap YAML file (e.g. provisioning/bootstrap.yaml) that replicates the current bootstrap behaviour: create superuser + organisation + project
• Make the bootstrap command delegate to provision with the bootstrap YAML file
• Keep the three sub-commands (createinitialadminuser, createinitialorganisation, createinitialproject) available for backwards compatibility

make reset → flush + provision

• Create provisioning/dev/ directory with YAML files for a rich local dev setup
• Update make reset to:

  reset: docker-up
      poetry run python manage.py flush --no-input
      poetry run python manage.py migrate
      poetry run python manage.py createcachetable
      poetry run python manage.py provision --directory provisioning/dev/

• Retire the seed logic from PR feat(API): Add make reset command for local development #6459 in favour of the YAML-based approach

Acceptance criteria

• python manage.py bootstrap still works and produces the same result
• make reset uses provisioning YAML and produces a usable dev environment
• Old bootstrap environment variables (ADMIN_EMAIL, etc.) still work via ${VAR:default} interpolation
• 100% test coverage for new/changed code
• Passes make typecheck and make lint

[khvn26]

Too soon.