Companion 0.5.28 — backup & restore (#128), NIP-46 remote signer (#139), companion-gated install pitch (#61 residual)

The companion-agent queue from the 2026-08-30 handoff, complete:

- Backup & Restore: hub sub-page, SAF export/import sealed in the
  node's ADR-005 envelope (Argon2id + ChaCha20-Poly1305, byte-compatible
  with core backup.rs), merge-only restore, no cloud.
- Remote Signer: the phone is the NIP-46 bunker — nsec generate/import,
  nostrconnect:// QR pairing (scanner + OS deep link), per-request
  approve/deny card, NIP-44 v2 transport with NIP-04 receive fallback,
  wire-faithful to rust-nostr's reference bunker. Crypto pinned to the
  official NIP-44 + BIP-340 vectors; e2e harness included.
- #61 residual: banner + manual intro trigger + overlay all gate on
  isCompanionApp() (web-side, vitest-covered).
- Hub modal: new sub-pages like Nodes/FIPS, 70% height cap, node ULA
  display/copy in the Nodes list, fipssh Termux helper (npub→ULA is a
  pure public-key function — verified against the fips crate).

Issues #61 (comment), #128, #139 closed on the tracker.

neode-ui/src/views/discover/CompanionBanner.vue

@@ -1,8 +1,11 @@
 <template>
   <!-- Companion app banner — same format as the featured app banner, with a
        phone mockup rising out of the right edge. Clicking anywhere (or the
-       Install button) opens the Remote Companion download/pairing modal. -->
+       Install button) opens the Remote Companion download/pairing modal.
+       Not rendered at all inside the companion app's WebView: pitching
+       "install the companion" to someone already in it is noise (#61). -->
   <div
+    v-if="showPitch"
     class="featured-banner companion-banner glass-card mb-8 relative overflow-hidden cursor-pointer"
     @click="openCompanionIntro()"
   >
@@ -41,7 +44,11 @@
 </template>
 
 <script setup lang="ts">
+import { computed } from 'vue'
+import { isCompanionApp } from '@/utils/openExternal'
 import { openCompanionIntro } from '@/composables/useCompanionIntro'
+
+const showPitch = computed(() => !isCompanionApp())
 </script>
 
 <style scoped>