panel: preserve out-of-range object refs in editor dropdowns

Real-world programs reference object indexes well past the coordinator's
discovery range — typical example from a live OmniPro II: a program
that's "Turn ON Unit 33025" where the unit number is a raw byte value
from undecoded extended-output addressing. The discovered units bucket
only covers slots up to ~511, so 33025 doesn't match any entry.

Before this commit the dropdown silently fell through to the first
known unit (e.g. ROOM ONE), making it look like the user had selected
that unit. The underlying draft.pr2 stayed at 33025, but a user who
glanced at the form and clicked Save would either preserve the original
(if they didn't touch the select) or accidentally clobber it with the
first list item (if they did).

Fix: _bucketWithPreserve prepends a synthesized option
"(undiscovered <kind> <idx> — preserve original)" when the current
value isn't represented. Applies in all four picker sites:

  * Action object picker (Unit / Zone / Area / Button for action commands)
  * EVENT trigger Button picker
  * EVENT trigger Zone picker
  * EVENT trigger Unit picker

The synthesized entry sits at the top of the list (visually distinct)
and is the selected default. Picking any other entry from the dropdown
then becomes an explicit choice — no more silent coercion.

Smoke-tested against the real panel: slot #1 (WHEN OPEN BIG GAR →
Turn ON Unit 33025) now shows "#33025 (undiscovered unit 33025 —
preserve original)" as the selected Unit option. Screenshots updated.

custom_components/omni_pca/frontend/src/omni-panel-programs.ts

@@ -441,6 +441,33 @@ export class OmniPanelPrograms extends LitElement {
     }
   }
 
+  /** Augment a bucket with a "preserve original" option if ``current``
+   * isn't represented by any entry. Real-world programs reference object
+   * indexes far past the discovered range (e.g. raw byte values from
+   * undecoded extended-output addressing on Omni Pro II — Unit 33025).
+   * Without this option the form silently coerces such values to the
+   * first known entry, which looks like the user already selected it.
+   *
+   * The synthesized entry is prepended so it's visually distinct (top
+   * of the list) and labelled to make the situation obvious.
+   */
+  private _bucketWithPreserve(
+    bucket: NamedObject[] | null,
+    kind: string,
+    current: number,
+  ): NamedObject[] {
+    const list = bucket ?? [];
+    if (current === 0) return list;            // 0 = "no object", no synth
+    if (list.some((o) => o.index === current)) return list;
+    return [
+      {
+        index: current,
+        name: `(undiscovered ${kind} ${current} — preserve original)`,
+      },
+      ...list,
+    ];
+  }
+
   private _onObjectChange(e: Event): void {
     const value = parseInt((e.target as HTMLSelectElement).value, 10);
     if (Number.isFinite(value)) this._patchDraft({ pr2: value });
@@ -965,11 +992,14 @@ export class OmniPanelPrograms extends LitElement {
 
   private _renderEventCategoryFields(decoded: DecodedEvent): TemplateResult {
     if (decoded.category === "button") {
+      const buttons = this._bucketWithPreserve(
+        this._objects?.buttons ?? null, "button", decoded.button ?? 0,
+      );
       return html`
         <label class="block">
           Button
           <select @change=${this._onEventButtonChange}>
-            ${(this._objects?.buttons ?? []).map((b) => html`
+            ${buttons.map((b) => html`
               <option .value=${String(b.index)}
                       ?selected=${b.index === decoded.button}>
                 #${b.index} ${b.name}
@@ -979,11 +1009,14 @@ export class OmniPanelPrograms extends LitElement {
         </label>`;
     }
     if (decoded.category === "zone") {
+      const zones = this._bucketWithPreserve(
+        this._objects?.zones ?? null, "zone", decoded.zone ?? 0,
+      );
       return html`
         <label class="block">
           Zone
           <select @change=${this._onEventZoneChange}>
-            ${(this._objects?.zones ?? []).map((z) => html`
+            ${zones.map((z) => html`
               <option .value=${String(z.index)}
                       ?selected=${z.index === decoded.zone}>
                 #${z.index} ${z.name}
@@ -1002,11 +1035,14 @@ export class OmniPanelPrograms extends LitElement {
         </label>`;
     }
     if (decoded.category === "unit") {
+      const units = this._bucketWithPreserve(
+        this._objects?.units ?? null, "unit", decoded.unit ?? 0,
+      );
       return html`
         <label class="block">
           Unit
           <select @change=${this._onEventUnitChange}>
-            ${(this._objects?.units ?? []).map((u) => html`
+            ${units.map((u) => html`
               <option .value=${String(u.index)}
                       ?selected=${u.index === decoded.unit}>
                 #${u.index} ${u.name}
@@ -1097,7 +1133,13 @@ export class OmniPanelPrograms extends LitElement {
 
   private _renderActionSection(draft: ProgramFields): TemplateResult {
     const cmdOpt: CommandOption | undefined = commandOptionFor(draft.cmd ?? 0);
-    const objectBucket = cmdOpt?.ref_kind ? this._pickBucket(cmdOpt.ref_kind) : null;
+    const objectBucket = cmdOpt?.ref_kind
+      ? this._bucketWithPreserve(
+          this._pickBucket(cmdOpt.ref_kind),
+          cmdOpt.ref_kind,
+          draft.pr2 ?? 0,
+        )
+      : null;
     const showsLevelPercent = (draft.cmd === 9);  // UNIT_LEVEL
     return html`
       <fieldset>