Correct pocket dimensions, liners, and cushion shadows

[darrinm]

The pockets had raised entrance rims, rails crossing the openings, and exposed green rings around their drops. Correct the pocket construction and use shared dimensions for the cushion geometry, physics, and rendering.

• Set corner mouths to 4.5 inches with 1-inch shelves and 142° facings; set side mouths to 5 inches with 0.125-inch shelves and 104° facings.
• Cut all six openings through the rail frame and fit recessed dark liners while keeping the cloth approach clear.
• Make soft cushion shadows follow the jaws and clip to the actual pocket holes.
• Use the official Astra Pool logo in the gameplay HUD.
• Update historical AI fixtures for the revised geometry while preserving current safety and performance assertions.

Validation: 343 tests passed, 26 physics checks passed, and production build passed. Inspected all six pockets from overhead and angled views. Added checks for dimensions, gentle and firm pocketing, rail clearance, and liner clearance.