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+# Step 3 — Implementation Detail
+
+1. Added tests/test_agent.py for TSD generation and required sections.
+2. Added XML parsing and mxGraphModel assertions for architecture.drawio validation.
+3. Added manifest JSON shape validation and required-input rejection coverage.
+4. Added pyproject.toml package metadata, pytest configuration, and CLI entry point.
+5. Added docs/validation-report.md describing automated and human-reviewable checks.