feat: add ide helper for better type checks

[glitchedmob]

Add laravel-ide-helper so facades, fluent helpers, and Eloquent models have proper type annotations for both IDE autocompletion and static analysis.

• Add barryvdh/laravel-ide-helper for generating docblocks
• Generate _ide_helper.php with facade/fluent/Eloquent helpers (committed)
• Generate model PHPDocs directly into source files with all properties nullable
• Create ForceNullablePropertiesHook to auto-nullify model properties on generation
• Run rector + pint after ide-helper regeneration to keep generated code lint-clean
• Fix DropboxAuthController for nullable model properties (?? '', ?? null)
• Exclude _ide_helper.php from phpstan and pint

[ThingEngineer]

This was all I could find: adding @composer ide-helper to post-update-cmd might cause surprise failures during composer update, especially on machines/CI where the app DB/env isn’t fully ready yet. It also means dependency updates can rewrite model docs/helper files and leave a dirty working tree unexpectedly. Maybe keep IDE helper generation opt-in (or at least gated to local/dev) so composer update stays predictable.