docs(smoke): clarify review height and opening policy

[7alexhuang-ux]

Summary

• define when smoke-exhaust review should use Room height versus modeled Ceiling elements
• require review and Excel export to use the same ceiling-height source
• document the project-confirmed opening ratios: projected/top-hung 1.0, casement 0.5, horizontal sliding 0.5, fixed 0
• keep unknown windows visibly flagged even when temporarily assumed as projected
• standardize the formal name 橫拉窗 (Horizontal Sliding Window)

Validation

• repository QA/QC: 61 PASS, 0 FAIL
• upstream contribution scope: only domain/smoke-exhaust-review.md