Implement an N3FJP live log source adapter

[rwjblue]

Context

N3FJP contest loggers expose a documented local TCP API and have dedicated NAQP software. Supporting that API would extend Sidecar beyond the N1MM-family ecosystem without adding logger, rig-control, or keying responsibilities.

This adapter should reuse the source lifecycle, completeness, persistence, and reconciliation design established by #27 rather than creating a parallel ingestion architecture.

Scope

• Document the N3FJP API commands, event messages, and capabilities needed for read-only NAQP log synchronization.
• Add configurable connection settings with conservative localhost defaults.
• Establish a trustworthy initial-log baseline before presenting the source as complete.
• Normalize contact additions, edits, and deletions when the API exposes them.
• Capture logger identity, event/category metadata, current frequency/band, and totals when available.
• Keep logger-reported totals as reconciliation evidence, not the scoring authority.
• Reconnect with bounded backoff, preserve last-good state, and expose stale/incomplete status.
• Use a local fake TCP server and sanitized protocol fixtures; automated tests must not depend on a live logger.
• Keep any spot or lookup capability independently gated by Centralize assistance policy across all live external sources #22's assistance policy.
• Document supported N3FJP products/versions and explicitly report unsupported behavior.

Acceptance criteria

• The adapter can establish a tested session with the documented login/handshake sequence.
• A complete initial NAQP log can be loaded and normalized without duplicate contacts.
• Supported add, edit, and delete behavior updates normalized state idempotently.
• Missing baseline, disconnect, malformed response, and unsupported-version states are visible.
• Reconnection cannot silently turn an incomplete delta stream into a complete log.
• Last-good scoring remains available while the source is degraded.
• A fake-server suite covers handshake, initial load, live changes, reconnect, and protocol errors.
• Contact telemetry is treated as local log data rather than QSO-finding assistance.
• Configuration and privacy documentation is included.

Dependencies and references

• Depends on the reusable source/reconciliation design from Add a reconciled N1MM-family live log source #27.
• Must comply with Centralize assistance policy across all live external sources #22.
• N3FJP API documentation: https://n3fjp.com/help/api.html
• N3FJP NAQP software: https://www.n3fjp.com/naqp.html