Add Notes page with Google Sheet/zip import-export

[artisanphil]

Summary

Adds a new "Notes" step to the language pack wizard, positioned between Games and Export. Users can add free-text notes, view them listed in the order added with a sequential number and created/updated timestamps, edit them inline, and delete them (with confirmation). Notes also round-trip through the existing Google Sheet import/export flow and are included in the zip export.

Changes

Notes page (CRUD)

• notes table migration (languagepackid, text, timestamps)
• Note model + LanguagePack::notes() relation
• NotesController (extends BaseItemController) — list (paginated), add, inline bulk edit, and delete
• notes.blade.php view, following the existing Resources/Games page conventions, including a delete-confirmation step before removal
• Routes for GET/POST/PATCH/DELETE on languagepack/notes/{languagePack}
• Wizard step added to langpacksteps.blade.php, wired into ExportController's completedSteps, and games.blade.php's "Next" link now points to Notes

Google Sheet & zip export/import

• ExportSheetService::notesSheet() writes real data (#, Note, CreatedAt, UpdatedAt) to the "notes" tab instead of a static placeholder
• ImportSheetService::saveNotes() imports the notes tab back into the notes table, defaulting created_at/updated_at to the current datetime when sheet values are empty
• GenerateZipExportService::generateNotesFile() writes aa_notes.txt (tab-delimited, same format as other aa_*.txt files) into the zip export

Tests

• NotesControllerTest — list ordering, add, edit, delete, cancel delete, and the checkbox → confirmation flow
• ExportServiceTest — aa_notes.txt content and timestamp defaults
• ImportSheetServiceTest — imported notes keep provided timestamps and default missing ones

Testing

All new and existing tests pass:

php artisan test --filter="NotesControllerTest|ExportServiceTest|ImportSheetServiceTest"