fix: preserve authored wall paths across identity barrier

Issue: #282
User-Visible: yes

src/houseplan-card.ts

@@ -7353,7 +7353,15 @@ class HouseplanCard extends LitElement {
     let safe = false;
     try {
       const afterSpace = committedCandidate.spaces.find((space: any) => space.id === before.spaceId);
-      safe = wallModelOffGridValueCount(afterSpace) <= wallModelOffGridValueCount(historyBefore)
+      // A completed point of the active, grid-snapped chain is authored input,
+      // even before its first draft record exists in `before`. Include that
+      // transient carrier in the growth baseline; later conversion from draft
+      // to room/partition must not count the same coordinate as newly derived.
+      const authoredPoints = this._path.length >= 2
+        ? this._path.map((point) => [point[0] / NORM_W, point[1] / NORM_W])
+        : [];
+      safe = wallModelOffGridValueCount(afterSpace)
+        <= wallModelOffGridValueCount(historyBefore, authoredPoints)
         && this._checkSpacePhysicalGeometry(committedCandidate, before.spaceId).ok;
     } catch {
       safe = false;
@@ -13692,7 +13700,7 @@ class HouseplanCard extends LitElement {
       else delete sp.walls;
     }
 
-    this._commitPhysicalGeometry(this._t('history.wall_face_batch'), before);
+    if (!this._commitPhysicalGeometry(this._t('history.wall_face_batch'), before)) return;
     delete this._resumeDraftBySpace[this._space];
     this._path = [];
     this._activeDraftId = null;

src/wall-segment-model.ts

@@ -80,7 +80,9 @@ const canonicalSpan = (a: number[], b: number[]): [Point, Point] => (
 const lengthOf = (a: number[], b: number[]): number => Math.hypot(b[0] - a[0], b[1] - a[1]);
 
 /** Unique authored/derived contour coordinates that are materially off-grid. */
-export const wallModelOffGridValueCount = (space: any): number => {
+export const wallModelOffGridValueCount = (
+  space: any, additionalPoints: readonly (readonly number[])[] = [],
+): number => {
   const values = new Set<string>();
   const inspect = (value: unknown): void => {
     const number = Number(value);
@@ -101,6 +103,9 @@ export const wallModelOffGridValueCount = (space: any): number => {
       inspect(segment?.b?.[0]); inspect(segment?.b?.[1]);
     }
   }
+  for (const additionalPoint of additionalPoints) {
+    inspect(additionalPoint?.[0]); inspect(additionalPoint?.[1]);
+  }
   return values.size;
 };
 const projectT = (p: number[], a: number[], b: number[]): number => {