Iso 2.0 [12/12]: Full Integration Scene — All Nano Kinds, Player, Walkability, 60 FPS

[putersdcat]

Spec reference

IsoRenderingPlanV2.1.md §8 Final Validation Scene; entire spec

Goal

A single render_nano_scene call (or browser screenshot) that shows ALL systems
working simultaneously:

• Base terrain: 3+ biomes visible
• Stone wall perimeter
• Fence run with gate
• River with troll-bridge crossing
• Tall-grass patches
• Cathedral or homestead assembly
• 2+ player sprites at various positions (inside fence, at gate, on bridge)
• Shadows visible on wall tiles
• Player behind fence (partially visible through gaps)
• Player behind wall (hidden)
• 60+ FPS confirmed

Acceptance criteria (ALL required to close)

• Single PNG ProgressEvaluations/integration-scene-final.png ≥ 900×600px showing all of the above.
• All 12 prior issues must be closed (with their PNGs committed) before this issue can be closed.
• PR merging experiment/isometric-2.0 findings into main src/ opened and linked in comment.
• Both [EPIC] Rendering depth & parallax overhaul — research spike + implementation plan #184 (rendering overhaul epic) and this epic (#iso-2.0-reboot) updated with final PR link.