Pass VM sync run IDs to proxbox-api

[emersonfelipesp]

Closes #519.

Summary

• Generate one VM sync run_id per Proxbox sync job.
• Persist the run ID in job data for inspection.
• Send the run ID to VM-stage SSE requests, including targeted per-VM routes.

Tests

• uv run ruff check netbox_proxbox/jobs.py netbox_proxbox/sync_stages.py netbox_proxbox/sync_params.py netbox_proxbox/schemas/sync_result.py tests/test_jobs.py tests/test_schemas.py
• uv run pytest tests/test_jobs.py tests/test_schemas.py tests/test_sync_params_flag_flattening.py tests/test_vm_sync_device_flag_enforcement.py -q
• uv run pytest -q

Note

This PR expects the companion backend PR in emersonfelipesp/proxbox-api to be merged/released so the forwarded run_id is consumed by proxbox-api.