[wass08]

What does this PR do?

Door and window casing fields (casingFaceA, casingFaceB, casingWidth, from #1193) were zod defaults, so parsing any saved door or window wrote all three. A scene's load paths then disagreed (the hosted app's client and authority loads compare them), and an untouched opening changed on its next save.

They are now optional, like other recent optional node fields: loading adds nothing. Absent faces are uncased; an absent width reads as 2 in through openingCasingWidth. New doors and windows still write casing on, so behaviour is unchanged.

How to test

1. Open a scene saved before casing: its doors and windows have no casing, and saving it changes no door or window fields.
2. Place a new door and window: casing shows on both faces; the panel's Casing section toggles and resizes it.
3. bun run ci: passes (run locally).

Screenshots / screen recording

N/A — non-visual change

Checklist

• I've tested this locally with bun dev
• My code follows the existing code style (run bun check to verify)
• I've updated relevant documentation (if applicable)
• This PR targets the main branch

🤖 Generated with Claude Code

---

Note

Medium Risk
This touches persisted door/window schema and load/save parity across client and authority; wrong handling could still mutate legacy scenes or desync casing on merge/move, though behavior is heavily covered by tests.

Overview
Door and window casing (casingFaceA, casingFaceB, casingWidth) no longer get Zod defaults when a node is parsed, so legacy openings load without those keys and stay uncased until someone turns casing on. Runtime behavior is unchanged: missing faces mean no boards; missing width still resolves to 2 in via openingCasingWidth.

Tests and round-trip expectations were updated (legacy corpus, scene migration, wall merge, floorplan move commit types) so they assert field absence or undefined instead of false / injected defaults. Preview/plan tests now use openingCasingWidth(node) rather than assuming casingWidth is always on the node.

^{Reviewed by Cursor Bugbot for commit f80ce2c. Bugbot is set up for automated code reviews on this repo. Configure here.}