Windows 1.0.0 runtime: /scenes and /scene/<id> routes return HTTP 500 (root canvas works)

[williamsaulniercourtier-eng]

Environment

• Windows 11 Home (10.0.26200), @pascal-app/cli 1.0.0, Node 24.15.0
• Runtime 1.0.0 started via pascal start + pascal editor --no-open
• Editor healthy at http://pascal.localhost:60994; MCP service healthy on loopback (scenes save/load via MCP work fine)

Repro

1. pascal start && pascal editor --no-open
2. Navigate directly to /scenes, or to /scene/<id> (any saved scene, project-bound or not)

Actual: HTTP 500 server-side. The page renders the error boundary: "This page couldn't load — A server error occurred. Reload to try again." (error id 3227098399 in one case). Client console shows a minified React error #441. Navigating client-side from / to /scenes (clicking "Open saved scenes") fails the same way after the route transition.

Expected: the scenes list / scene editor routes render.

Notes

• The root / route and the full editor canvas load and work; only the scenes/scene routes 500 (both on direct load and after client-side navigation).
• MCP is unaffected: create_room → save_scene → load_scene round-trips geometry exactly on this same install, so the data layer is fine — this looks like an SSR/prerender route issue in the web runtime.
• Happy to test a fix on this machine.