app: accurate Shizuku handoff — name the steps, add developer-options shortcut

Verified against Shizuku 13.6's manifest (pulled APK, aapt2 xmltree): its
wireless-debugging entry points (AdbPairingTutorialActivity,
AdbPairingService, StarterActivity) have no intent filters, so they are
not exported and cannot be launched externally; MainActivity answers only
MAIN/LAUNCHER with no deep link. Starting wireless debugging from another
app is therefore not possible, which is why the handoff lands on the
root-start screen.

Instead the hint now names the exact steps inside Shizuku ("Pairing", then
"Start"), and a second tap opens Developer options — that action IS public
and exported, and Wireless debugging has to be on before Shizuku's
wireless start works.

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

echolot-app/app/src/main/kotlin/app/echo_lot/app/MainActivity.kt

@@ -65,6 +65,13 @@ class MainActivity : ComponentActivity() {
                         state = vm.state,
                         onRun = { vm.run() },
                         onCancel = vm::cancel,
+                        onDeveloperOptions = {
+                            runCatching {
+                                startActivity(
+                                    app.echo_lot.shizuku.ShizukuAvailability.developerOptionsIntent()
+                                )
+                            }
+                        },
                         onShizukuAction = {
                             // Shizuku can only be started from its own app (the pairing flow lives
                             // there), so send the user straight to it; if it is already running we
@@ -114,6 +121,7 @@ private fun EcholotScreen(
     onRun: () -> Unit,
     onCancel: () -> Unit,
     onShizukuAction: () -> Unit,
+    onDeveloperOptions: () -> Unit,
     onExport: (MeasurementDocument) -> Unit,
 ) {
     Column(
@@ -150,6 +158,17 @@ private fun EcholotScreen(
                         Text(it, fontSize = 11.sp, fontWeight = FontWeight.SemiBold,
                             color = Color(0xFFFFB454))
                     }
+                    // Wireless debugging must be ON before Shizuku's wireless start works, and
+                    // that screen (unlike Shizuku's pairing activity) is publicly launchable.
+                    if (state.shizukuState ==
+                        app.echo_lot.shizuku.ShizukuAvailability.State.INSTALLED_NOT_RUNNING
+                    ) {
+                        Text(
+                            "Wireless debugging settings →",
+                            Modifier.padding(top = 6.dp).clickable { onDeveloperOptions() },
+                            fontSize = 11.sp, color = Color(0xFF35E0C4),
+                        )
+                    }
                 }
             }
         }