filtering: hiding is an explicit per-device flag (docs/FILTERING.md)

Agreed with the owner: whether a device is on the plan is a CHECKBOX
('Hide device from plan', every kind incl. virtual), not a runtime
algorithm. The old filter survives only as the SEEDER of those flags.

- marker.hidden is the flag; hidden devices are BUILT (room LQI counts
  them — owner's decision) but rendered only in the device editor with
  'Show hidden' on, ghosted. They cast no glow and no light fill: an
  invisible device casts no visible light (owner's decision).
- seedHiddenBindings(): non-physical devices (excluded domains, Group,
  scene, bridge, myheat children, grouped lamps) in bound areas WITHOUT a
  marker. The editing client materialises them into hidden:true stub
  markers, sets settings.filter_seeded, retires settings.show_all, and
  strips fresh-hidden ids from the red-dot list. Unticking the checkbox
  keeps a hidden:false marker — the seeder never revisits a marked device,
  so the user's decision is final. New non-physical devices hide silently;
  physical ones keep the red-dot flow.
- legacy configs (no filter_seeded) keep the OLD behaviour verbatim —
  runtime filter, shared show_all, hidden-means-gone — until an editing
  client materialises them, so a read-only tablet never sees a half-state.
- 'Show all' is renamed 'Show hidden' and is LOCAL to the tab; the shared
  settings.show_all retires with the runtime filter.
- 'Remove from plan' disappears for auto/entity devices (the checkbox is
  the way); a virtual device's Delete remains a real deletion.
- docs/FILTERING.md is the source of truth for the mechanism.

Tests: seeder/seeded/legacy/lights units (146), smoke_hidden_flag with 12
assertions (68 smokes). Inventory: 146 / 51 / 43 / 68.

demo/smoke_hidden_flag.mjs

@@ -0,0 +1,69 @@
+// docs/FILTERING.md: скрытие — явная галка. Конфиг материализуется сеятелем
+// (filter_seeded), галка в диалоге у всех устройств, «Показать скрытые» —
+// локальный режим редактора, скрытые рисуются призраками и только там.
+import { launch, checkAll, finish } from './serve.mjs';
+const { page, browser } = await launch();
+const out = {};
+
+// --- сеятель материализует конфиг при загрузке ---------------------------
+out.configSeeded = await page.evaluate(async () => {
+  const c = window.__card;
+  const t0 = Date.now();
+  while (!c._serverCfg?.settings?.filter_seeded && Date.now() - t0 < 3000) {
+    await new Promise((r) => setTimeout(r, 60));
+  }
+  return c._serverCfg?.settings?.filter_seeded === true;
+});
+
+// --- галка прячет, счётчик не считает, призрак только в редакторе --------
+Object.assign(out, await page.evaluate(async () => {
+  const o = {};
+  const c = window.__card;
+  const sr = () => c.shadowRoot || c.renderRoot;
+  const visibleIds = () => [...sr().querySelectorAll('.dev')].length;
+  const before = visibleIds();
+
+  const d = c._devices.find((x) => x.space === 'f1' && x.bindingKind === 'device');
+  c._serverCfg.markers = c._serverCfg.markers || [];
+  c._serverCfg.markers.push({ id: d.id, binding: 'device:' + d.bindingRef, hidden: true });
+  c._cfgEpoch++; c._regSignature = '';
+  c._maybeRebuildDevices(); c.requestUpdate(); await c.updateComplete;
+
+  o.hiddenNotRendered = visibleIds() === before - 1;
+  const built = c._devices.find((x) => x.id === d.id);
+  o.stillBuilt = !!built && built.hidden === true;
+  o.countExcludesHidden = (sr().querySelector('.count')?.textContent || '').includes(String(before - 1));
+
+  // в просмотре тумблера нет эффекта — призраки только в редакторе устройств
+  c._showHidden = true; c.requestUpdate(); await c.updateComplete;
+  o.noGhostsInView = !sr().querySelector('.dev.ghost');
+  c._setMode('devices'); c.requestUpdate(); await c.updateComplete;
+  o.ghostInEditor = !!sr().querySelector('.dev.ghost');
+  // тумблер локальный: конфиг не трогается
+  o.toggleIsLocal = c._serverCfg.settings.show_all === undefined;
+
+  // --- галка в диалоге у авто-устройства, кнопки «Удалить» нет -----------
+  const ghost = c._devices.find((x) => x.id === d.id);
+  c._openMarkerDialog(ghost); await c.updateComplete;
+  o.checkboxOn = c._markerDialog?.hideFromPlan === true;
+  o.noDeleteForAuto = !sr().querySelector('.dialog .btn.danger');
+  // снимаем галку и сохраняем — маркер остаётся с hidden:false (анти-повтор)
+  c._markerDialog = { ...c._markerDialog, hideFromPlan: false };
+  await c._saveMarker(); await c.updateComplete;
+  const m = (c._serverCfg.markers || []).find((x) => x.binding === 'device:' + d.bindingRef);
+  o.untickKeepsMarker = !!m && m.hidden === false;
+  const back = c._devices.find((x) => x.id === d.id) || c._devices.find((x) => x.bindingRef === d.bindingRef);
+  o.deviceVisibleAgain = !!back && !back.hidden;
+
+  // --- у виртуального кнопка «Удалить» есть -------------------------------
+  c._openMarkerDialog(); await c.updateComplete;
+  c._markerDialog = { ...c._markerDialog, name: 'Тест', binding: 'virtual' };
+  await c._saveMarker(); await c.updateComplete;
+  const virt = c._devices.find((x) => x.virtual);
+  c._openMarkerDialog(virt); await c.updateComplete;
+  o.deleteForVirtual = !!sr().querySelector('.dialog .btn.danger');
+  c._markerDialog = null; c._setMode('view');
+  return o;
+}));
+
+await finish(browser, checkAll(out));