Fix Android navigation and enforce secure-only messaging

- Remove forced redirect to pairing screen for users without a couple
- Users now go directly to dashboard after onboarding (matches iOS behavior)
- Add secureReady state to InputBar to prevent sending before E2EE is ready
- Pre-fetch admin key during key initialization to reduce chat load time
- Block media uploads until encryption is fully ready
- Add security status indicator in chat when encryption is initializing

apps/mobile/app/index.tsx

@@ -2,36 +2,32 @@ import { Redirect } from "expo-router";
 import { useAuthStore } from "../src/store";
 import { View, ActivityIndicator, StyleSheet } from "react-native";
 
-export default function Index() {
-    const { isAuthenticated, isLoading, user } = useAuthStore();
-
-    // Show loading state
-    if (isLoading) {
-        return (
-            <View style={styles.container}>
-                <ActivityIndicator size="large" color="#e94560" />
-            </View>
-        );
-    }
-
-    // Redirect based on auth state
-    if (!isAuthenticated) {
-        return <Redirect href="/(auth)/login" />;
-    }
-
-    // If user hasn't completed onboarding, go to onboarding first
-    if (!user?.onboarding_completed) {
-        return <Redirect href="/(app)/onboarding" />;
-    }
-
-    // If user has no couple, go to pairing
-    if (!user?.couple_id) {
-        return <Redirect href="/(app)/pairing" />;
-    }
-
-    // Otherwise go to home
-    return <Redirect href="/(app)" />;
-}
+export default function Index() {
+    const { isAuthenticated, isLoading, user } = useAuthStore();
+
+    // Show loading state while auth is being determined
+    if (isLoading) {
+        return (
+            <View style={styles.container}>
+                <ActivityIndicator size="large" color="#e94560" />
+            </View>
+        );
+    }
+
+    // Redirect based on auth state
+    if (!isAuthenticated) {
+        return <Redirect href="/(auth)/login" />;
+    }
+
+    // If user hasn't completed onboarding, go to onboarding first
+    if (!user?.onboarding_completed) {
+        return <Redirect href="/(app)/onboarding" />;
+    }
+
+    // Go to home/dashboard - users can pair from within the app
+    // No forced redirect to pairing for users without a couple
+    return <Redirect href="/(app)" />;
+}
 
 const styles = StyleSheet.create({
     container: {