feat(android): align native preview with measured PWA design

android/app/src/main/java/community/yuvomi/mobile/PwaPresentation.kt

@@ -0,0 +1,107 @@
+package community.yuvomi.mobile
+
+import java.time.LocalDate
+import java.time.ZoneId
+import java.time.ZonedDateTime
+import java.time.format.DateTimeFormatter
+import java.util.Locale
+import org.json.JSONArray
+import org.json.JSONObject
+
+val pwaSupportedWidgets = listOf("tasks", "calendar", "shopping", "notes")
+
+/** Presentation only. Household business rules and permissions remain server-owned. */
+fun pwaGreeting(displayName: String, hour: Int): String {
+    val first = displayName.trim().split(Regex("\\s+")).firstOrNull().orEmpty()
+    val greeting = when (hour) {
+        in 5..11 -> "Guten Morgen"
+        in 12..17 -> "Guten Tag"
+        else -> "Guten Abend"
+    }
+    return if (first.isBlank()) greeting else "$greeting, $first"
+}
+
+fun pwaDueLabel(value: String, today: LocalDate = LocalDate.now()): String {
+    if (value.isBlank()) return ""
+    val date = runCatching { LocalDate.parse(value.take(10)) }.getOrNull() ?: return value
+    return when (date) {
+        today -> "Heute fällig"
+        today.plusDays(1) -> "Morgen fällig"
+        today.minusDays(1) -> "Gestern fällig"
+        else -> date.format(DateTimeFormatter.ofPattern("d. MMM", Locale.GERMAN))
+    }
+}
+
+fun pwaPriority(value: String) = when (value) {
+    "low" -> "Niedrig"
+    "medium" -> "Mittel"
+    "high" -> "Hoch"
+    "urgent" -> "Dringend"
+    else -> ""
+}
+
+fun pwaGroup(value: String) = value.takeUnless { it.isBlank() || it in setOf("general", "other", "misc") } ?: "Sonstiges"
+
+fun NativeState.householdNow(instant: java.time.Instant = java.time.Instant.now()): ZonedDateTime {
+    val zone = runCatching { ZoneId.of(preferences.text("timezone_effective").ifBlank { preferences.text("timezone") }) }
+        .getOrDefault(ZoneId.systemDefault())
+    return instant.atZone(zone)
+}
+
+fun NativeState.moduleVisible(module: String): Boolean = access(module) != "none" &&
+    listOf("disabled_modules", "hidden_modules").none { key ->
+        val values = preferences.optJSONArray(key) ?: JSONArray()
+        (0 until values.length()).any { values.optString(it) == module }
+    }
+
+fun NativeState.dashboardTiles(): List<String> {
+    val config = preferences.rows("dashboard_widgets")
+    return (
+        if (preferences.isNull("dashboard_widgets")) {
+            pwaSupportedWidgets
+        } else {
+            config.filter { it.optBoolean("visible", true) }.map { it.text("id") }
+        }
+        )
+        .filter { it in pwaSupportedWidgets && moduleVisible(it) && widget(it) }.distinct()
+}
+
+fun pwaWidgetVisibility(preferences: JSONObject, visible: Set<String>, editable: Set<String> = pwaSupportedWidgets.toSet()): JSONArray {
+    val existing = preferences.rows("dashboard_widgets")
+    val rows = if (preferences.isNull("dashboard_widgets")) {
+        pwaSupportedWidgets.mapIndexed { index, id ->
+            JSONObject().put("id", id).put("visible", true).put("order", index).put("size", "1x1")
+        }
+    } else {
+        existing
+    }
+    val result = JSONArray(
+        rows.map { row ->
+            JSONObject(row.toString()).apply {
+                if (text("id") in editable && text("id") in pwaSupportedWidgets) put("visible", text("id") in visible)
+            }
+        },
+    )
+    val configured = rows.map { it.text("id") }.toSet()
+    pwaSupportedWidgets.filter { it in visible && it in editable && it !in configured }.forEach { id ->
+        result.put(JSONObject().put("id", id).put("visible", true).put("order", result.length()).put("size", "1x1"))
+    }
+    return result
+}
+
+fun NativeState.nativeTabs(): List<NativePage> {
+    val order = preferences.optJSONArray("mobile_nav_order")?.let { array ->
+        (0 until array.length()).map { array.optString(it) }
+    }.orEmpty()
+    val pages = (order + listOf("tasks", "kitchen", "notes")).mapNotNull {
+        when (it) {
+            "tasks" -> NativePage.TASKS
+            "shopping", "kitchen" -> NativePage.SHOPPING
+            "notes" -> NativePage.NOTES
+            else -> null // Unimplemented modules are never fake navigation targets.
+        }
+    }.distinct().filter { moduleVisible(it.name.lowercase()) }
+    return listOf(NativePage.HOME) + pages + NativePage.MORE
+}
+
+fun NativePage.navigationLabel() = if (this == NativePage.SHOPPING) "Küche" else title