Increase SSH test container session limits

[arnestrickmann]

Summary

• raise OpenSSH MaxSessions in the Docker SSH test fixture
• raise MaxStartups to allow more concurrent connection attempts during SSH feature testing

Testing

• Not run; pushed first so SSH reproduction/fix work can continue separately.

[greptile-apps]

Greptile Summary

This PR raises two OpenSSH server limits in the Docker-based SSH test fixture to support higher-concurrency SSH feature testing. The changes are append-only to sshd_config and are scoped entirely to the test container.

• MaxSessions 100 increases the per-multiplexed-connection session cap from the OpenSSH default of 10 to 100, allowing more simultaneous channels on a single TCP connection during tests.
• MaxStartups 100:30:200 raises the concurrent-unauthenticated-connection window from the default 10:30:100 to 100:30:200, matching the higher concurrency expected during SSH feature test runs.

Confidence Score: 5/5

Safe to merge — changes are confined to a test-only Docker fixture and do not touch application code.

Both directives are appended correctly to sshd_config with valid syntax. The MaxStartups format (start:rate:full) is used correctly. The container already ships with hardcoded password credentials and a fully open sudo policy, so raising connection limits does not meaningfully change its security posture. No application logic is affected.

No files require special attention.

Important Files Changed

Filename	Overview
testing/docker-ssh/dockerfile	Raises MaxSessions to 100 and MaxStartups to 100:30:200 in the SSH test fixture sshd_config; also adds a trailing newline at EOF.

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