## Description
This PR fixes installation instability on Apple Silicon (M1/M2/M3) Macs caused by the "Rosetta Trap".
The Problem:
When a terminal runs under Rosetta, scripts using `uname -m` incorrectly detect Intel. This leads to wrong binary downloads and Homebrew path issues.
The Fix:
1. scripts/postinstall.js: Added check for sysctl.proc_translated.
2. apps/macos/.../CLIInstaller.swift: Added native Swift guard.
3. scripts/check-env.sh: Added diagnostic utility.
## AI/Vibe-Coded 🤖
- [x] AI-Assisted: Marked in title/description.
- [x] Testing Level: Fully Tested (Verified on M1 environment with check-env.sh).
- [x] Transparency: Prompts derived from installation_debugging.md analysis.
- [x] I understand what this code does
