refactor: keep room warm-draft construction in the lazy editor (#762)

Issue: #762
User-Visible: no

docs/ARCHITECTURE.md

@@ -489,6 +489,10 @@ still recognised in stored config but no longer served
   render, including the card-local header offset for pending chrome (#762).
   Adoption completion lives in the lazy editor graph: it only executes after
   that runtime is ready; View retains just cancellation and camera comparison.
+  The room draft payload is also built by the installed editor runtime.
+  This moves existing room-state reads across the already-defined editor port;
+  it adds no room state. #762 records the resulting host-reference/ported-private
+  counts in the monolith baseline, without widening its tolerance bands.
 
 ## Second card: houseplan-space-card (read-only)
 

scripts/monolith-baseline.json

@@ -1,8 +1,8 @@
 {
   "delegates": 154,
   "portMembers": 347,
-  "hostRefs": 4885,
-  "portPrivates": 94,
+  "hostRefs": 4925,
+  "portPrivates": 103,
   "harnessPrivates": 100,
   "bundleBytes": 2605172
 }

src/houseplan-card.ts

@@ -3432,17 +3432,7 @@ export class HouseplanCard extends LitElement {
       const data = this[`_${kind}Dialog`];
       if (data) return at(kind, data);
     }
-    if (this._roomDialog) {
-      return at('room', {
-        editId: this._roomEditId, fill: this._roomFill, customFill: this._roomCustomFill,
-        tempMin: this._roomTempMin, tempMax: this._roomTempMax, tempSrc: this._roomTempSrc,
-        humSrc: this._roomHumSrc, srcOpen: this._roomSrcOpen, srcFilter: this._roomSrcFilter,
-        nameScale: this._roomNameScale, labelScale: this._roomLabelScale,
-        areaSel: this._areaSel, nameSel: this._nameSel,
-        pendingSplit: this._pendingSplit, wallFaceBatch: this._wallFaceBatch,
-        path: this._path,
-      });
-    }
+    if (this._roomDialog) return at('room', this._editorRuntimeOrThrow().warmRoomDraft());
     if (this._spaceDialog) return this._spaceDialog.busy ? null : at('space', this._spaceDialog);
     return null;
   }

src/houseplan-editor-runtime.ts

@@ -922,6 +922,19 @@ public finishWarmModeAdoption(request: number): void {
 public resumeWarmMode(mode: 'view' | 'plan' | 'devices' | 'decor', animate: boolean): void {
   resumeWarmMode(this.host as unknown as WarmModeHost, mode, () => this.host._setMode(mode, animate, true));
 }
+/** An open room editor implies an installed runtime; View never constructs this payload. */
+public warmRoomDraft() {
+  const host = this.host;
+  return {
+    editId: host._roomEditId, fill: host._roomFill, customFill: host._roomCustomFill,
+    tempMin: host._roomTempMin, tempMax: host._roomTempMax, tempSrc: host._roomTempSrc,
+    humSrc: host._roomHumSrc, srcOpen: host._roomSrcOpen, srcFilter: host._roomSrcFilter,
+    nameScale: host._roomNameScale, labelScale: host._roomLabelScale,
+    areaSel: host._areaSel, nameSel: host._nameSel,
+    pendingSplit: host._pendingSplit, wallFaceBatch: host._wallFaceBatch,
+    path: host._path,
+  };
+}
 
 public _setMode(mode: 'view' | 'plan' | 'devices' | 'decor', animate = true): void {
     if (mode !== this.host._mode) this.host._cancelDangerConfirm();