test: add satellite profile run to the network simulation test suite

[Etoile-Bleu]

Summary

The network simulation (tests/network_scenario.sh) supports a satellite profile (1200ms latency, 100 kbps) but there is no automated test run for it. Add a CI-ready satellite scenario.

Context and motivation

The satellite profile is the harshest realistic network condition in the test suite. Proving convergence under 1200ms latency + 100 kbps bandwidth is important for NGO deployments in remote areas.

Exact task

1. In tests/network_scenario.sh (or a new tests/satellite_scenario.sh), add a satellite run:

   • 4 clinics, 200 events each, satellite profile
   • Hub-con mode (--max-peers 16)
   • Assert all 800 events converge on the hub

2. Add a GitHub Actions job in .github/workflows/e2e-network.yml (or a new workflow) that runs this scenario and uploads the HTML report as an artifact

3. The test must complete in under 10 minutes on a standard GitHub Actions runner (ubuntu-latest)

Acceptance criteria

• Satellite scenario runs to completion without error
• Report shows 800/800 events on hub
• GitHub Actions job is labeled satellite-sim and appears in the workflow tab

Estimated effort

~2-4 h -- medium (new flag or filter, integration test)