Scaffold native Android build and enforce Rust boundaries (#89)

android/features/src/main/AndroidManifest.xml

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+<manifest />

android/features/src/main/kotlin/de/rfc1437/ironstorage/features/ShellScreen.kt

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+package de.rfc1437.ironstorage.features
+
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.CircularProgressIndicator
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.NavigationBar
+import androidx.compose.material3.NavigationBarItem
+import androidx.compose.material3.Scaffold
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.semantics.heading
+import androidx.compose.ui.semantics.semantics
+import androidx.compose.ui.unit.dp
+import androidx.lifecycle.compose.collectAsStateWithLifecycle
+import de.rfc1437.ironstorage.core.ShellState
+import de.rfc1437.ironstorage.core.ShellTab
+
+@Composable
+fun ShellScreen(viewModel: ShellViewModel) {
+    val snapshot by viewModel.snapshot.collectAsStateWithLifecycle()
+    Scaffold(
+        bottomBar = {
+            NavigationBar {
+                ShellTab.entries.forEach { tab ->
+                    NavigationBarItem(
+                        selected = snapshot.selectedTab == tab,
+                        onClick = { viewModel.selectTab(tab) },
+                        icon = {},
+                        label = { Text(tab.name) }
+                    )
+                }
+            }
+        }
+    ) { padding ->
+        Column(
+            modifier = Modifier.fillMaxSize().padding(padding).padding(24.dp),
+            verticalArrangement = Arrangement.spacedBy(16.dp)
+        ) {
+            Text(stringResource(R.string.app_name), style = MaterialTheme.typography.headlineLarge)
+            val page = snapshot.pages.firstOrNull { it.tab == snapshot.selectedTab }
+            Text(
+                page?.stateTitle ?: stringResource(R.string.scaffold_title),
+                modifier = Modifier.semantics { heading() },
+                style = MaterialTheme.typography.headlineSmall
+            )
+            Text(page?.detail ?: stringResource(R.string.scaffold_detail))
+            if (snapshot.state == ShellState.Loading) CircularProgressIndicator()
+        }
+    }
+}

android/features/src/main/kotlin/de/rfc1437/ironstorage/features/ShellViewModel.kt

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+package de.rfc1437.ironstorage.features
+
+import androidx.lifecycle.ViewModel
+import dagger.hilt.android.lifecycle.HiltViewModel
+import de.rfc1437.ironstorage.core.ShellRepository
+import de.rfc1437.ironstorage.core.ShellTab
+import javax.inject.Inject
+
+@HiltViewModel
+class ShellViewModel @Inject constructor(private val repository: ShellRepository) : ViewModel() {
+    val snapshot = repository.snapshot
+
+    fun selectTab(tab: ShellTab) = repository.selectTab(tab)
+}

android/features/src/main/res/values/strings.xml

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+<resources>
+    <string name="app_name">IronStorage</string>
+    <string name="scaffold_title">No Password Store</string>
+    <string name="scaffold_detail">Your password store has not been configured.</string>
+</resources>