Dining Room Expanded to 3-Column Grid, Chair Sprite Iteration

The dining room grew from 4 tables to the 3-column/12-table layout the game still uses today (3 vertical columns, each a paired 4-top north and south plus a standalone 2-top in between — see createDefaultRestaurant in Restaurant.js). The outside queue became a real single-file line rather than a loose cluster. Chair art went through two successive sprite swaps (chair2, then chair3) chasing a cleaner look, plus an empty-chair cutout fix and a chair-hole resize.