Make Nodeus federation operational

[NovasPlace]

This turns the existing ALEPH/Nodeus federation design into a runnable, operator-controlled implementation.

Changes:

• fix FastAPI startup lifecycle so Docker/uvicorn initializes the DB and validates runtime config
• fix broken v1 query/deposit aliases
• align Docker/data-path/runtime environment
• make setup.sh generate a complete environment and support modern docker compose
• add explicit peer-to-peer federation with cursored pull sync
• preserve original agent identity/provenance on replicated chunks without awarding local reputation
• contact only operator-configured peers; no scanning or autonomous installation
• export only memories explicitly tagged for federation (default tag: federate)
• keep federation disabled until the operator opts in
• add federation status/manual sync endpoints
• add smoke tests and GitHub Actions CI

Validation:

• GitHub Actions smoke job passes on Python 3.12
• health, key provisioning, deposit/search, v1 alias, federation export, and federation status are exercised

This is intentionally a safe first operational mesh: federation requires explicit configuration and explicit export tagging.