Add local TCP/UDP probe listener and MTR pass/fail reporting

[ehsanking]

Motivation

• Provide a minimal, dependency-free listener that can be enabled on an Iran-hosted server to verify TCP/UDP reachability without requiring internet egress or extra packages.
• Make test results easier for non-technical users by showing MTR as a clear pass/fail (tick/cross) with loss% instead of relying on an opaque numeric score.

Description

• Added a new CLI command listener that starts a local TCP and/or UDP echo probe using Node built-ins (net and dgram) and is configurable via --host, --port, and --protocol.
• Integrated an MTR stage into the connectivity checks (mtrAvailable, mtrLossPercent, mtrRawSample, and stageResults.mtr) by invoking mtr when present and mapping loss to pass/fail/no-data/unavailable.
• Updated detailed CLI reporting to display MTR as a check/ cross plus loss% for provider best-connections and per-connection details, replacing the user-facing provider score line with the MTR result for clarity.
• No new dependencies were introduced and existing scoring/behaviour remain intact for other programmatic outputs.

Testing

• Ran the automated test suite with npm test and all tests passed (6 tests, 0 failures).

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Codex Task