feat: add Protect camera/RTSPS management, masked config init, auto-generated schema

[MinhPho]

Description

Adds UniFi Protect camera management, RTSPS stream lifecycle, and two quality-of-life improvements:

• Protect cameras: protect cameras list, protect cameras show via integration API (API key); --full flag for direct Protect API (cookie auth with --username/--password)
• RTSPS streams: protect rtsps list, protect rtsps create, protect rtsps delete with quality validation and camera resolution by name or ID
• Masked config init: secrets (api-key, password) hidden during interactive config init using rpassword; optional --username/--password prompts for Protect credentials
• Auto-generated schema: schema command now walks clap's Command tree at runtime instead of maintaining a hand-written JSON literal; domain metadata (output_fields, mutating, note) layered on top

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Testing

• Tests added/updated
• All tests passing (401 tests)
• Manual testing performed (live against UDM Pro + Protect)

Checklist

• Code follows project style (cargo clippy clean)
• Conventional commit messages used
• Documentation updated (if needed)
• CHANGELOG.md updated (if user-facing)