[AXTRACK]

Why

• Final audit found that COMPLETED did not strictly validate the legacy InitializeResult, the safe fixture did not prove receipt of notifications/initialized, and filesystem evidence mixed install/runtime changes.

Change

• Validate legacy 2025-06-18 InitializeResult fields and negotiated version.
• Make the safe fixture record receipt of notifications/initialized and assert it in runtime CI.
• Split filesystem observations into INSTALL and EXERCISE phases.
• Add negative unit tests for malformed/wrong-version initialize results.
• Align README guarantees with the implemented legacy-only profile.

Non-goals

• No modern 2026-07-28 MCP profile.
• No new adapters, credentials, network modes, or verdict semantics.

Validation

• Harness CI deterministic tests and controlled runtime fixtures must pass before merge.