core/viewer: StairOpeningSystem, material library expansion, and UI refinements

.agents/skills/open-pr/SKILL.md

@@ -1,10 +1,10 @@
 ---
 name: open-pr
-description: Open a pull request on pascalorg/editor using the repo's PR template. Use when the user asks to open/create a PR, push and PR, or ship a branch in the editor repo.
+description: Open or update a pull request on pascalorg/editor using the repo's PR template. Use when the user asks to open/create a PR, push and PR, ship a branch, or refresh a PR description after new commits in the editor repo.
 allowed-tools: Bash(git *) Bash(gh *) Read
 ---
 
-Open a pull request against `pascalorg/editor` from the current branch.
+Open a pull request against `pascalorg/editor` from the current branch, or — if a PR for the branch already exists — push new work and reconcile the PR description against the current `main..HEAD` delta.
 
 ## 1. Pre-flight
 
@@ -16,8 +16,13 @@ git log --oneline main..HEAD
 
 Stop if:
 - The current branch is `main`. Ask the user to create a feature branch first.
-- The branch has no commits ahead of `main`. Nothing to open a PR for.
-- There are uncommitted changes the user hasn't asked to commit.
+- The branch has no commits ahead of `main` **and** no uncommitted changes. Nothing to ship.
+
+If there are **uncommitted changes**, do not silently skip them:
+
+1. Show the user `git status` and `git diff --stat`.
+2. Ask for a commit message (do not auto-generate — this is an explicit "ship it" moment).
+3. Stage the intended files and create the commit with the user-provided message.
 
 Run a build sanity check if the change is non-trivial:
 
@@ -26,36 +31,50 @@ bun typecheck
 bun build
 ```
 
-Don't open the PR with a broken build.
+Don't open or update the PR with a broken build.
 
 ## 2. Read the PR template
 
-The template is at `.github/pull_request_template.md`. Read it before composing the body — the section headings and checklist items are the source of truth, not your memory of them.
+The template is at `.github/pull_request_template.md`. Read it before composing or reconciling the body — the section headings and checklist items are the source of truth, not your memory of them.
 
 ```bash
 cat .github/pull_request_template.md
 ```
 
-Mirror the template exactly:
+Template sections (mirror exactly):
 
-- `## What does this PR do?` — one paragraph or a short bullet list. Link related issues with `Fixes #123` when applicable.
-- `## How to test` — numbered, concrete reviewer steps (commands to run, what to click, expected outcome).
-- `## Screenshots / screen recording` — if the change is visual, paste a recording link or note that one will be added. If purely non-visual (refactor, internal API), say so explicitly so the reviewer knows nothing is missing.
-- `## Checklist` — copy the boxes verbatim, ticking the ones already verified.
+- `## What does this PR do?` — one paragraph or short bullet list. Link related issues with `Fixes #123`.
+- `## How to test` — numbered, concrete reviewer steps.
+- `## Screenshots / screen recording` — link, or `N/A — non-visual change` if it doesn't apply.
+- `## Checklist` — the boxes from the template, verbatim.
 
-## 3. Push and open
+## 3. Push
 
 ```bash
 git push -u origin HEAD
 ```
 
-Check for an existing PR first:
+This updates an existing PR's commits/files automatically if one is already open. The description, however, does **not** auto-update — that's what step 5 handles.
+
+## 4. Detect existing PR
+
+```bash
+gh pr view --json url,number,title,body 2>/dev/null
+```
+
+- If the command returns nothing → no PR exists → go to **step 5a (create)**.
+- If it returns a PR → capture `url`, `number`, `title`, `body` → go to **step 5b (reconcile)**.
+
+## 5a. Create (no existing PR)
+
+Compose the body from the current `main..HEAD` delta:
 
 ```bash
-gh pr view --json url 2>/dev/null
+git log --oneline main..HEAD
+git diff --stat main...HEAD
 ```
 
-If none exists, create it. Pass the body via HEREDOC to preserve markdown formatting:
+Fill the template sections based on that delta. Then:
 
 ```bash
 gh pr create --title "short, scope-prefixed title" --body "$(cat <<'EOF'
@@ -85,13 +104,45 @@ EOF
 
 Keep the title under ~70 characters. Use a scope prefix when there's an obvious one (`viewer:`, `core:`, `editor:`, `mcp:`).
 
-If a PR already exists, print its URL and stop — don't recreate.
+## 5b. Reconcile (existing PR)
+
+**Goal:** keep what's still accurate in the existing description (including any manual edits the user made in the GitHub UI), update what's now wrong, and add what's missing. Do **not** blindly overwrite.
+
+Steps:
+
+1. Re-read the existing body captured in step 4.
+2. Compute the current delta:
+   ```bash
+   git log --oneline main..HEAD
+   git diff --stat main...HEAD
+   git diff main...HEAD
+   ```
+3. Section by section, produce a reconciled body:
+   - **What does this PR do?** — Keep existing sentences/bullets that still describe the branch. Rewrite or remove ones that no longer match the diff. Add bullets for new commits/features not yet mentioned.
+   - **How to test** — Keep existing steps that still work. Update commands/paths that have changed. Add steps for new behavior. Remove steps for behavior that was reverted or removed.
+   - **Screenshots / screen recording** — Preserve existing links verbatim. If the change is now visual and no link exists, note `<link to be added>` rather than removing the section.
+   - **Checklist** — **Preserve the user's checkbox states exactly** (ticked or unticked). Do not re-tick based on this run's verification. If a box is unchecked but you verified its condition (e.g. `bun check` passed), surface a *note in the final report* — do not modify the box.
+4. Preserve the template's section order and headings.
+5. Write the reconciled body back:
+
+   ```bash
+   gh pr edit --body "$(cat <<'EOF'
+   <reconciled body>
+   EOF
+   )"
+   ```
+
+   Update `--title` too **only if** the scope clearly changed (e.g. branch started as `editor:` work but now also touches `core:`). Otherwise leave the title alone.
+
+If a reconcile would produce a body identical to the existing one, skip `gh pr edit` and note "description already up to date" in the report.
 
-## 4. Report
+## 6. Report
 
 Return:
 
 - PR URL
-- Title used
+- Whether the PR was **created** or **updated** (and if updated, whether the description was changed or already up to date)
+- Title used (and whether it was changed)
+- Commits pushed this run (from `git log`)
 - Local typecheck/build status (if you ran them)
-- A note for the reviewer if anything in the checklist is left unchecked
+- Notes for the reviewer about any unchecked checklist items whose conditions you verified this run

packages/core/src/index.ts

@@ -44,10 +44,10 @@ export {
 } from './lib/door-operation'
 export { getRenderableSlabPolygon } from './lib/slab-polygon'
 export {
+  type AutoSlabSyncPlan,
   detectSpacesForLevel,
   initSpaceDetectionSync,
   planAutoSlabsForLevel,
-  type AutoSlabSyncPlan,
   type Space,
   wallTouchesOthers,
 } from './lib/space-detection'
@@ -89,6 +89,7 @@ export { default as useLiveTransforms, type LiveTransform } from './store/use-li
 export { clearSceneHistory, default as useScene } from './store/use-scene'
 export { resolveElevatorDispatchTarget } from './systems/elevator/elevator-dispatch'
 export {
+  type ElevatorDoorSide,
   getElevatorCabCenterZ,
   getElevatorCabDepth,
   getElevatorCabWidth,
@@ -101,7 +102,6 @@ export {
   getResolvedElevatorDoorPanelStyle,
   getResolvedElevatorDoorStyle,
   getResolvedElevatorShaftStyle,
-  type ElevatorDoorSide,
 } from './systems/elevator/elevator-geometry'
 export { syncAutoElevatorOpenings } from './systems/elevator/elevator-opening-sync'
 export { ElevatorOpeningSystem } from './systems/elevator/elevator-opening-system'
@@ -125,6 +125,7 @@ export {
   resolveElevatorServiceLevels,
 } from './systems/elevator/elevator-service'
 export { syncAutoStairOpenings } from './systems/stair/stair-opening-sync'
+export { StairOpeningSystem } from './systems/stair/stair-opening-system'
 export {
   getClampedWallCurveOffset,
   getMaxWallCurveOffset,
@@ -157,8 +158,8 @@ export {
   constrainWallMoveDeltaToAxis,
   getPerpendicularWallMoveAxis,
   planWallMoveJunctions,
-  type WallMoveBridgePlan,
   type WallMoveAxis,
+  type WallMoveBridgePlan,
   type WallMoveJunctionPlan,
   type WallPlanPoint,
 } from './systems/wall/wall-move'