feat: add opt-in codegen consistency check

[longvo92]

WHAT

• add an opt-in CLI CURRENT-tree RTE/ARXML consistency check
• support configurable rule severities, forbidden prefixes, and ignored port patterns
• gate consistency failures with exit code 1 and incomplete checks with exit code 2
• document the workflow in English and Vietnamese
• prepare release 1.18.0

WHY

Generated C can disagree with ARXML even when an old/new file diff is individually valid. The check is opt-in so existing CLI, viewer, and HTML-report workflows remain unchanged.

VALIDATION

• 834 unittest tests passed
• Ruff passed
• Mypy passed
• release preflight for 1.18.0 passed
• CLI smoke: default disabled, opt-in failure gates even with --exit-zero

Action needed

Review and merge. After merge, run the release workflow once with version 1.18.0 and publish enabled.