Ship contract-verified Bedrock waterparks

[gildaltar]

Why

The Aqua Meridian iPhone test exposed two release-blocking problems: the deployed generator silently converted attraction requests into generic megabase massing, and Bedrock exports were possible without a valid semantic contract. The resulting pack contained 221,200 raw placements, eight materials, and no water.

What changed

• Add a dedicated waterpark compiler family with a wave pool, lazy river, three supported water slides, splash pad, locker room, food court, lifeguard stations, lighting, and safe entrances/spawn.
• Extend executable contract checks to prove requested waterpark features, including a requested slide count.
• Treat the Bedrock stable token as exact synchronized registry coverage.
• Translate canonical directional/slab/lantern/pillar states to Bedrock command-state names.
• Add a fail-closed bedrock_mcpack export with row compression, 64-block fill caps, 32 commands/tick by default, paged controllers, bounded ticking areas, cancellation, and cleanup.
• Refuse all exports from invalid or uncertified builds.
• Add a deterministic Aqua Meridian release generator and update the packaged runtime to 0.7.0.

Verification

• tsc --noEmit
• Skybridge production build (telemetry disabled)
• npm test: 184 passed, 1 platform-specific test skipped
• .mcpack ZIP integrity: clean
• Aqua Meridian: 83,455 placements, 17 materials, 10,256 water blocks, 16/16 hard requirements passed, 0 blocking issues
• Mobile installer: 9,056 commands (89.15% reduction), 32 commands/tick, maximum 2,048 block changes/tick