feat: add AppleSiliconAdapterEvidence normalization design and fixtures

[Copilot]

• Explore repo structure and understand existing patterns
• Add design doc: docs/APPLE_SILICON_EVIDENCE_NORMALIZATION.md
• Add raw evidence fixture: examples/apple-silicon-evidence/raw-apple-silicon-evidence.example.json
• Add normalized evidence fixture: examples/apple-silicon-evidence/normalized-boot-evidence.example.json
• Add Makefile validation for new fixture JSON (python -m json.tool)
• Update repo.maturity.yaml next actions and evidence
• make validate passes (all 5 fixture paths: PASS)
• python -m pytest passes (8/8 tests)
• No-op commit pushed to re-trigger CI after workflow approval

[mdheller]

@copilot Scope appears aligned with issue #15, but this PR is still draft and CI is action-required. Please mark it ready when complete and push a no-op commit if needed after workflow approval. Keep scope docs/fixtures/validation only and retain validation evidence.

[Copilot]

@copilot Scope appears aligned with issue #15, but this PR is still draft and CI is action-required. Please mark it ready when complete and push a no-op commit if needed after workflow approval. Keep ...

No-op commit pushed (dff22dc) to re-trigger CI. Scope remains docs/fixtures/validation only — no host mutation, SEP calls, or runtime changes. Validation evidence:

make validate → PASS (all 5 fixture paths)
python -m pytest → 8/8 passed

Please mark ready for review once CI clears.

[mdheller]

Agent triage: scope matches issue #15 and changed files are bounded to docs, fixtures, Makefile validation, and maturity metadata.

This cannot merge yet because the PR is still draft and CI is action_required.

Please mark this PR ready for review and refresh or rebase if needed so checks run under current repo settings. Keep scope unchanged.