Compact Meadow Isle region maps

[season179]

Summary

• compact all eight Meadow Isle region grids while preserving the region graph, encounter tables, topic routing, and world-map positions
• co-locate arc, trail, and payoff anchors with canonical region data and add traversal-density guards
• migrate old Meadow coordinates once through worldLayoutRevision, preserving the region and all player progress
• update the Meadow plan and desktop smoke route for the compact layouts

Validation

• npm test — 542/542 passing
• npm run typecheck — passing
• npm run check:metas — passing
• Cocos Creator 3.8.8 headless web build — exit 36 (documented success), fresh game/build/web-mobile/index.html
• live 1280×720 browser smoke — Harbor → Dock → Woolly → Ticktock → Orchard → Festival → Barn → Gardens → Dock → Harbor; zero console errors
• live old-save probe — Orchard revision 0 coordinate (28,20) resumed at compact Orchard spawn (10,1), checkpointed revision 1, and resumed exactly there on second load

Closes #86