[P5] Additional templates: cli-starter, celery-worker (phased)

[ulises-jeremias]

Future growth: add CLI and worker templates after fastapi-starter reaches CNA maturity.

[ulises-jeremias]

Tracking for this phased work lives in docs/FUTURE_TEMPLATES.md (added via #43) after fastapi-starter reached CNA-style maturity for docs/architecture/CI.

Leaving this issue open as the backlog item for implementing cli-starter and celery-worker in a later phase.

[ulises-jeremias]

Tracking note (2026-07-17)

Related growth work was split so this issue stays focused on cli-starter + celery-worker:

• Extension pack v1 → [P5] Extension pack v1: sqlalchemy, redis, sentry, auth (parity with CNA addons) #48
• FastAPI maturity checklist → [P4] FastAPI starters maturity checklist (M1 parity pass) #49
• django-api → [P5] Additional template: django-api (phased after cli-starter / celery-worker) #50 (was in maturity plan Tier 5 but not listed here)

Layered CI (#46/#47) is done — new templates must land with L1 coverage and use uvx from PyPI only in CI.