fix: bitcoin receive, AIUI pointer input, electrs self-heal, OTA timeout

- LND wallet: request correct address type so receive-address generation
  no longer 400s
- AIUI/app session: on-screen pointer can click + type into app content
  (incl. app store search); "open in new tab" opens the phone browser;
  mobile credential modal centered instead of full-height
  (remote-relay.ts, AppSession.vue, AppSessionFrame.vue, AppIconGrid.vue,
  openExternal.ts, WebViewScreen.kt) + remote-relay tests
- health_monitor: electrs auto-recovers from a corrupt index and shows a
  percent/block-height progress screen while reindexing (useElectrsSync.ts)
- update.rs: drop retired tx1138 secondary mirror (one-time migration);
  longer download timeout for slow connections
- CHANGELOG: v1.7.90-alpha notes
- tests/release/run.sh: harness tweaks

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

neode-ui/src/composables/useElectrsSync.ts

@@ -0,0 +1,57 @@
+import { ref, computed, onUnmounted } from 'vue'
+
+/** Shape of GET /electrs-status (see core electrs_status.rs ElectrsSyncStatus). */
+export interface ElectrsSyncStatus {
+  indexed_height: number
+  bitcoin_height: number
+  network_height: number
+  progress_pct: number
+  status: string // "starting" | "waiting" | "syncing" | "indexing" | "synced" | "error"
+  stale: boolean
+  error: string | null
+  index_size: string | null
+  tor_onion: string | null
+}
+
+/**
+ * Polls GET /electrs-status while active. Used to show an ElectrumX sync screen
+ * *before* the real Electrum UI — the Electrum server only accepts client
+ * connections (and the UI only works) once the on-chain index is built, which
+ * is a long initial process.
+ *
+ * Fails OPEN: if the status can't be fetched we report not-syncing, so a status
+ * outage never blocks the normal iframe path. We only gate the UI when we
+ * positively know the index is still being built (status !== "synced").
+ */
+export function useElectrsSync() {
+  const status = ref<ElectrsSyncStatus | null>(null)
+  let timer: ReturnType<typeof setInterval> | null = null
+
+  async function poll() {
+    try {
+      const res = await fetch('/electrs-status', { cache: 'no-store' })
+      if (res.ok) status.value = (await res.json()) as ElectrsSyncStatus
+    } catch {
+      /* keep last known value; fail open */
+    }
+  }
+
+  function start() {
+    if (timer) return
+    void poll()
+    timer = setInterval(() => void poll(), 8000)
+  }
+
+  function stop() {
+    if (timer) {
+      clearInterval(timer)
+      timer = null
+    }
+  }
+
+  /** True only when we know ElectrumX is still building its index. */
+  const syncing = computed(() => !!status.value && status.value.status !== 'synced')
+
+  onUnmounted(stop)
+  return { status, syncing, start, stop }
+}