feat(ui): mesh header "Flash LoRa" button opens the in-app flash flow

Replaces the external flasher.meshcore.co.uk link with a button that
opens the global device-setup modal directly at its flash step, via a
new manual entry point in the mesh store (flashFlowPath). Manual opens
target the connected radio (else the first detected stick), skip the
read-only probe — the port is held by the live session and a second tty
opener corrupts it; the backend flash job stops the listener itself —
and close the modal instead of stepping back to the detection screen.
Button is disabled with a hint when no radio is present.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

neode-ui/src/components/mesh/MeshDeviceSetupModal.vue

@@ -340,7 +340,7 @@ function stopProbeProgress(done = false) {
   if (done) probeProgress.value = 100
 }
 
-const devicePath = computed(() => mesh.undismissedDetectedDevices[0] ?? '')
+const devicePath = computed(() => mesh.flashFlowPath ?? mesh.undismissedDetectedDevices[0] ?? '')
 const show = computed(() => !!devicePath.value)
 const imageFailed = ref(false)
 const deviceImage = computed(() =>
@@ -402,6 +402,23 @@ watch([show, devicePath], async ([visible]) => {
     stopFlashPoll()
     return
   }
+  if (mesh.flashFlowPath) {
+    // Manual "Flash LoRa" entry: jump straight to the flash step. Skip the
+    // read-only probe — the port is usually the live session's, and a second
+    // opener on the tty corrupts the running connection; status already
+    // knows the firmware kind for the connected radio.
+    probe.value = null
+    probeError.value = ''
+    probing.value = false
+    stopProbeProgress()
+    imageFailed.value = false
+    openFlashStep()
+    const t = (mesh.status?.device_type ?? '').toLowerCase()
+    if (t === 'meshcore' || t === 'meshtastic' || t === 'reticulum') {
+      flashFamily.value = t as FlashFirmwareFamily
+    }
+    return
+  }
   step.value = 1
   error.value = ''
   imageFailed.value = false
@@ -428,6 +445,10 @@ watch([show, devicePath], async ([visible]) => {
 }, { immediate: false })
 
 function dismiss() {
+  if (mesh.flashFlowPath) {
+    mesh.closeFlashFlow()
+    return
+  }
   if (devicePath.value) mesh.dismissDetectedDevice(devicePath.value)
 }
 
@@ -598,6 +619,11 @@ async function cancelFlash() {
 
 function closeFlashStep() {
   stopFlashPoll()
+  if (mesh.flashFlowPath) {
+    // Manual entry has no detection step to go back to — close the modal.
+    mesh.closeFlashFlow()
+    return
+  }
   step.value = 1
 }
 </script>