feat(commands): add /diagnose interactive troubleshooting assistant v3.0.4
- New diagnose.md command with bilingual support (FR/EN)
- 12 problem categories: permissions, MCP, config, performance, installation
- Auto-fetches latest guide from GitHub for up-to-date troubleshooting
- Integrates with audit-scan.sh --json for environment scanning
- Structured output: diagnostic → solution → template → reference
Updated: README, examples/README, CHANGELOG, cheatsheet, guide (section 10.4)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>