feat: add remote signer QR flow to AuthModal

- Introduced a new phase for remote signer login using QR codes, enhancing the authentication experience for desktop users.
- Implemented UI elements for displaying the QR code and handling user interactions, including error messages and loading states.
- Updated the Nostr Connect composable to support the new QR flow, including cancellation handling and improved error management.

These changes provide users with a seamless and modern way to authenticate using remote signers, improving overall usability.

src/components/AuthModal.vue

@@ -12,6 +12,57 @@
 
           <!-- ═══ NORMAL AUTH VIEW ═══ -->
           <template v-if="sovereignPhase === 'normal'">
+            <!-- ─── REMOTE SIGNER QR PHASE (desktop) ─── -->
+            <template v-if="remoteSignerPhase === 'qr'">
+              <div class="text-center">
+                <button
+                  @click="handleRemoteSignerBack"
+                  class="flex items-center gap-2 text-white/60 hover:text-white transition-colors mb-6 w-full justify-start"
+                >
+                  <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M15 19l-7-7 7-7" />
+                  </svg>
+                  Back
+                </button>
+
+                <div v-if="errorMessage" class="mb-4 p-3 rounded-lg bg-red-500/20 border border-red-500/30 text-red-400 text-sm text-left">
+                  {{ errorMessage }}
+                </div>
+
+                <h2 class="text-2xl font-bold text-white mb-2">Remote Signer</h2>
+                <p class="text-white/50 text-sm mb-6">Scan the QR code with your phone to sign in</p>
+
+                <!-- QR Code -->
+                <div class="bg-white rounded-2xl p-4 inline-block mb-5">
+                  <img v-if="remoteSignerQrDataUrl" :src="remoteSignerQrDataUrl" alt="Nostr Connect QR" class="w-56 h-56" />
+                  <div v-else class="w-56 h-56 flex items-center justify-center text-gray-400">
+                    Generating QR...
+                  </div>
+                </div>
+
+                <p v-if="nostrConnectLoading" class="text-sm text-white/70 animate-pulse mb-4">
+                  Waiting for signer...
+                </p>
+
+                <!-- Copy URI -->
+                <button
+                  @click="copyRemoteSignerUri"
+                  class="w-full bg-white/10 hover:bg-white/15 text-white rounded-xl px-4 py-3 text-sm font-medium transition-colors flex items-center justify-center gap-2 mb-4"
+                >
+                  <svg class="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                    <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M8 5H6a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2v-1M8 5a2 2 0 002 2h2a2 2 0 002-2M8 5a2 2 0 012-2h2a2 2 0 012 2m0 0h2a2 2 0 012 2v3m2 4H10m0 0l3-3m-3 3l3 3" />
+                  </svg>
+                  {{ remoteSignerCopyText }}
+                </button>
+
+                <p class="text-xs text-white/40">
+                  Use Primal, Amber, or any Nostr Connect signer app
+                </p>
+              </div>
+            </template>
+
+            <!-- ─── AUTH OPTIONS (idle) ─── -->
+            <template v-else>
             <!-- Header -->
             <div class="text-center mb-8">
               <h2 class="text-3xl font-bold text-white">
@@ -54,8 +105,23 @@
               </button>
             </form>
 
-            <!-- Login with Nostr (Primal) — default / first option -->
+            <!-- Remote Signer — desktop: QR phase; mobile: direct link -->
             <div class="mt-4 space-y-2">
+              <template v-if="isDesktop">
+                <button
+                  @click="handleRemoteSignerClick"
+                  :disabled="isLoading"
+                  class="nostr-login-button w-full flex items-center justify-center gap-2"
+                >
+                  <img
+                    src="@/assets/images/primal-icon.svg"
+                    alt="Remote Signer"
+                    class="w-5 h-5 shrink-0"
+                  />
+                  Remote Signer
+                </button>
+              </template>
+              <template v-else>
                 <button
                   v-if="!popupBlockedUri"
                   @click="handleNostrConnectLogin"
@@ -67,11 +133,11 @@
                     alt="Primal"
                     class="w-5 h-5 shrink-0"
                   />
-                {{ nostrConnectLoading ? 'Waiting for Primal...' : 'Login with Nostr (Primal)' }}
+                  {{ nostrConnectLoading ? 'Waiting...' : 'Remote Signer' }}
                 </button>
                 <template v-else>
                   <p class="text-sm text-white/70 text-center">
-                  Tap below to open Primal and sign in:
+                    Tap below to open your signer app:
                   </p>
                   <a
                     :href="popupBlockedUri"
@@ -81,12 +147,13 @@
                   >
                     <img
                       src="@/assets/images/primal-icon.svg"
-                    alt="Primal"
+                      alt="Signer"
                       class="w-5 h-5 shrink-0"
                     />
-                  Open Primal
+                    Open Signer App
                   </a>
                 </template>
+              </template>
             </div>
 
             <!-- Sign in with Nostr Extension (NIP-07) -->
@@ -258,6 +325,7 @@
               </button>
             </div>
             </template>
+          </template>
 
           <!-- ═══ SOVEREIGN PHASE: NAH! ═══ -->
           <div v-else-if="sovereignPhase === 'nah'" class="sovereign-nah" key="nah">
@@ -325,6 +393,7 @@
 
 <script setup lang="ts">
 import { ref, computed, watch } from 'vue'
+import QRCode from 'qrcode'
 import { useAuth } from '../composables/useAuth'
 import { useAccounts } from '../composables/useAccounts'
 import { useNostrConnect } from '../composables/useNostrConnect'
@@ -349,7 +418,20 @@ const emit = defineEmits<Emits>()
 
 const { loginWithNostr, isLoading: authLoading } = useAuth()
 const { loginWithExtension, loginWithPrivateKey } = useAccounts()
-const { loginWithRemoteSigner, isLoading: nostrConnectLoading, error: nostrConnectError, popupBlockedUri } = useNostrConnect()
+const {
+  loginWithRemoteSigner,
+  startRemoteSignerQrFlow,
+  isLoading: nostrConnectLoading,
+  error: nostrConnectError,
+  popupBlockedUri,
+} = useNostrConnect()
+
+const isDesktop = !/Android|webOS|iPhone|iPad|iPod|BlackBerry|IEMobile|Opera Mini/i.test(navigator.userAgent)
+const remoteSignerPhase = ref<'idle' | 'qr'>('idle')
+const remoteSignerQrDataUrl = ref('')
+const remoteSignerCopyText = ref('Copy URI')
+const remoteSignerUri = ref('')
+let remoteSignerCancel: (() => void) | null = null
 
 const mode = ref<'login' | 'register' | 'forgot'>(props.defaultMode)
 const errorMessage = ref<string | null>(null)
@@ -388,6 +470,11 @@ watch(() => props.isOpen, (open) => {
     errorMessage.value = null
     showNsecField.value = false
     nsecInput.value = ''
+    remoteSignerPhase.value = 'idle'
+    remoteSignerQrDataUrl.value = ''
+    remoteSignerUri.value = ''
+    remoteSignerCancel?.()
+    remoteSignerCancel = null
     cancelAmber()
   }
 })
@@ -398,6 +485,8 @@ watch(nostrConnectError, (err) => {
 })
 
 function closeModal() {
+  remoteSignerCancel?.()
+  remoteSignerCancel = null
   emit('close')
   errorMessage.value = null
   cancelAmber()
@@ -542,9 +631,67 @@ async function handleNostrLogin() {
   }
 }
 
+/**
+ * Desktop: Open Remote Signer QR phase.
+ */
+async function handleRemoteSignerClick() {
+  errorMessage.value = null
+  remoteSignerPhase.value = 'qr'
+  remoteSignerQrDataUrl.value = ''
+  remoteSignerUri.value = ''
+  remoteSignerCopyText.value = 'Copy URI'
+
+  try {
+    const { uri, complete, cancel } = startRemoteSignerQrFlow()
+    remoteSignerCancel = cancel
+    remoteSignerUri.value = uri
+
+    const dataUrl = await QRCode.toDataURL(uri, {
+      width: 224,
+      margin: 2,
+      color: { dark: '#000000', light: '#FFFFFF' },
+      errorCorrectionLevel: 'M',
+    })
+    remoteSignerQrDataUrl.value = dataUrl
+
+    await complete
+    emit('success')
+    closeModal()
+  } catch (error: any) {
+    if (remoteSignerPhase.value === 'qr') {
+      errorMessage.value = error?.message || 'Remote signer login failed. Please try again.'
+    }
+  } finally {
+    remoteSignerCancel = null
+  }
+}
+
+/**
+ * Back from Remote Signer QR phase.
+ */
+function handleRemoteSignerBack() {
+  remoteSignerCancel?.()
+  remoteSignerCancel = null
+  remoteSignerPhase.value = 'idle'
+  remoteSignerQrDataUrl.value = ''
+  remoteSignerUri.value = ''
+  errorMessage.value = null
+}
+
+async function copyRemoteSignerUri() {
+  if (!remoteSignerUri.value) return
+  try {
+    await navigator.clipboard.writeText(remoteSignerUri.value)
+    remoteSignerCopyText.value = 'Copied!'
+    setTimeout(() => { remoteSignerCopyText.value = 'Copy URI' }, 2000)
+  } catch {
+    remoteSignerCopyText.value = 'Copy failed'
+  }
+}
+
 /**
  * Login with Nostr via remote signer (Primal, etc.) using nostrconnect:// URI.
- * Opens the signer in a new tab, waits for connection, then creates backend session.
+ * Mobile: Opens the signer via link, waits for connection, then creates backend session.
  */
 async function handleNostrConnectLogin() {
   errorMessage.value = null

src/composables/useNostrConnect.ts

@@ -116,12 +116,92 @@ export function useNostrConnect() {
     }
   }
 
+  let qrFlowAbort: AbortController | null = null
+  let qrFlowUserCancelled = false
+
+  /**
+   * Start remote signer flow in QR mode (desktop).
+   * Returns the URI for the QR code and a promise that resolves when login completes.
+   * Does not open a window — user scans QR with their phone.
+   */
+  function startRemoteSignerQrFlow(): { uri: string; complete: Promise<void>; cancel: () => void } {
+    const clientSigner = new PrivateKeySigner()
+    const signer = new NostrConnectSigner({
+      relays: NOSTR_CONNECT_RELAYS,
+      signer: clientSigner,
+    })
+
+    const baseUri = signer.getNostrConnectURI({
+      name: 'IndeeHub',
+      url: window.location.origin,
+    })
+    const uri = appendCallbackToUri(baseUri)
+
+    isConnecting.value = true
+    error.value = null
+    qrFlowUserCancelled = false
+    qrFlowAbort = new AbortController()
+    const timeout = setTimeout(() => qrFlowAbort!.abort(), WAIT_FOR_SIGNER_TIMEOUT_MS)
+
+    const complete = (async () => {
+      try {
+        await signer.waitForSigner(qrFlowAbort!.signal)
+        clearTimeout(timeout)
+        qrFlowAbort = null
+
+        if (!signer.remote) {
+          throw new Error('Connection was closed before the signer responded.')
+        }
+
+        const pubkey = await signer.getPublicKey()
+        if (!pubkey) {
+          throw new Error('Could not get public key from signer.')
+        }
+
+        const account = new NostrConnectAccount(pubkey, signer)
+        accountManager.addAccount(account)
+        accountManager.setActive(account)
+        await authStore.loginWithNostr(pubkey, 'nostr-connect', {})
+      } catch (err: any) {
+        clearTimeout(timeout)
+        qrFlowAbort = null
+        if (!qrFlowUserCancelled) {
+          if (err?.name === 'AbortError' || err?.message?.includes('Aborted')) {
+            error.value = 'Connection timed out. Please try again.'
+          } else {
+            error.value = err?.message || 'Remote signer login failed. Please try again.'
+          }
+        }
+        throw err
+      } finally {
+        isConnecting.value = false
+        if (signer && !signer.isConnected) {
+          signer.close().catch(() => {})
+        }
+      }
+    })()
+
+    const cancel = () => {
+      qrFlowUserCancelled = true
+      clearTimeout(timeout)
+      qrFlowAbort?.abort()
+      qrFlowAbort = null
+      isConnecting.value = false
+      if (signer && !signer.isConnected) {
+        signer.close().catch(() => {})
+      }
+    }
+
+    return { uri, complete, cancel }
+  }
+
   return {
     isConnecting,
     isLoading,
     error,
     popupBlockedUri,
     loginWithRemoteSigner,
+    startRemoteSignerQrFlow,
     getCallbackUrl,
   }
 }