fix: drop the unreachable virtual-radio guard, keep honest evidence (#385 r2-M1)

An already-checked radio input fires no change event, so the same-binding
guard on the virtual branch was dead code and its smoke assert vacuous.
Removed both; a comment documents why the reset there is always
legitimate. The candidate-list guard (the reachable path) stays tested.

User-Visible: no
Issue: #385

src/houseplan-editor-runtime.ts

@@ -12251,13 +12251,10 @@ public _renderMarkerDialog(): TemplateResult {
             <label class="srcrow">
               <input type="radio" name="bmode" .checked=${d.bindingMode === 'virtual'}
                 @change=${() => {
-                  // #385(а): re-selecting the current binding must not reset
-                  // the configured value source or badge — spec #378 §1.6
-                  // demands the reset only on an actual CHANGE of binding.
-                  if (d.binding === 'virtual') {
-                    this.host._markerDialog = { ...d, bindingMode: 'virtual', bindingOpen: false };
-                    return;
-                  }
+                  // #385(а) r2-M1: no same-binding guard here on purpose — a
+                  // radio input fires no change event when it is already
+                  // checked, so this branch runs only on an actual switch to
+                  // virtual; the reset below is therefore always legitimate.
                   const next = {
                     ...d, bindingMode: 'virtual' as const, binding: 'virtual', bindingOpen: false,
                     controls: persistedExternalControls('virtual', d.controls),