refactor: nest-room launch port, KMP ICS export and Marmot group notices

- AppPlatform.openNestRoom starts the audio room; the live bubble and the
  nest lobby call it instead of NestActivity.launch.
- IcsExport moves to commonMain: UTC stamps and basic dates are computed
  on SearchDate instead of java.time (IcsExportTest still passes).
- Marmot create/edit screens toast through the shared notices;
  VoiceReplyViewModel names exceptions with KClass.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S7FuNBSKiyVecARSoE4B9P

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/platform/AndroidAppPlatform.kt

@@ -26,6 +26,7 @@ import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.UriHandler
+import com.vitorpamplona.amethyst.Amethyst
 import com.vitorpamplona.amethyst.BuildConfig
 import com.vitorpamplona.amethyst.commons.favorites.FavoriteApp
 import com.vitorpamplona.amethyst.commons.model.navigation.Route
@@ -37,6 +38,7 @@ import com.vitorpamplona.amethyst.commons.ui.settings.SettingsCategory
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
 import com.vitorpamplona.amethyst.favorites.FavoriteAppLauncher
 import com.vitorpamplona.amethyst.ui.navigation.topbars.AndroidAroundMeLocationLabel
+import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.activity.NestActivity
 import com.vitorpamplona.quartz.concord.cord02Community.ImagePointer
 import com.vitorpamplona.amethyst.commons.ui.navigation.bottombars.AppBottomBar as AppBottomBarImpl
 import com.vitorpamplona.amethyst.favorites.rememberManifestIconModel as AppRememberManifestIconModel
@@ -52,6 +54,9 @@ import com.vitorpamplona.amethyst.ui.screen.loggedIn.settings.legalSettingsCateg
 object AndroidAppPlatform : AppPlatform {
     override val isCastingAvailable: Boolean get() = BuildConfig.IS_CASTING_AVAILABLE
 
+    // NestActivity.launch adds FLAG_ACTIVITY_NEW_TASK, so the application context can start it.
+    override fun openNestRoom(addressValue: String) = NestActivity.launch(Amethyst.instance.appContext, addressValue)
+
     // Per flavour: Play links the hosted policies, F-Droid surfaces none.
     override fun legalSettingsCategory(uriHandler: UriHandler): SettingsCategory? = flavorLegalSettingsCategory(uriHandler)
 

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/marmotGroup/CreateGroupScreen.kt

@@ -20,7 +20,6 @@
  */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup
 
-import android.widget.Toast
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.consumeWindowInsets
@@ -42,7 +41,6 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.vitorpamplona.amethyst.commons.marmot.MarmotGroupIconChange
 import com.vitorpamplona.amethyst.commons.marmot.ui.MarmotRetentionChoice
@@ -60,6 +58,7 @@ import com.vitorpamplona.amethyst.commons.resources.marmot_keypackage_relays_not
 import com.vitorpamplona.amethyst.commons.resources.marmot_skip_for_now
 import com.vitorpamplona.amethyst.commons.resources.marmot_use_outbox_relays
 import com.vitorpamplona.amethyst.commons.service.uploads.SelectedMedia
+import com.vitorpamplona.amethyst.commons.ui.components.rememberLongNotice
 import com.vitorpamplona.amethyst.commons.ui.insets.imePaddingSafe
 import com.vitorpamplona.amethyst.commons.ui.loadStringRes
 import com.vitorpamplona.amethyst.commons.ui.navigation.navs.INav
@@ -93,7 +92,7 @@ fun CreateGroupScreen(
     var isCreating by remember { mutableStateOf(false) }
     var showKeyPackageRelayDialog by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
-    val context = LocalContext.current
+    val longNotice = rememberLongNotice()
 
     /**
      * Create the group, optionally after [prepare].
@@ -154,12 +153,7 @@ fun CreateGroupScreen(
             } catch (e: Exception) {
                 isCreating = false
                 launch(Dispatchers.Main) {
-                    Toast
-                        .makeText(
-                            context,
-                            loadStringRes(Res.string.marmot_failed_to_create_group, e.message),
-                            Toast.LENGTH_LONG,
-                        ).show()
+                    longNotice.show(loadStringRes(Res.string.marmot_failed_to_create_group, e.message))
                 }
             }
         }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/chats/marmotGroup/EditGroupInfoScreen.kt

@@ -20,7 +20,6 @@
  */
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.chats.marmotGroup
 
-import android.widget.Toast
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.consumeWindowInsets
@@ -40,7 +39,6 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.compose.collectAsStateWithLifecycle
 import com.vitorpamplona.amethyst.commons.marmot.MarmotGroupIconChange
@@ -58,6 +56,8 @@ import com.vitorpamplona.amethyst.commons.resources.marmot_group_name_placeholde
 import com.vitorpamplona.amethyst.commons.resources.marmot_legacy_group_no_avatar_url
 import com.vitorpamplona.amethyst.commons.resources.save
 import com.vitorpamplona.amethyst.commons.service.uploads.SelectedMedia
+import com.vitorpamplona.amethyst.commons.ui.components.rememberLongNotice
+import com.vitorpamplona.amethyst.commons.ui.components.rememberShortNotice
 import com.vitorpamplona.amethyst.commons.ui.insets.imePaddingSafe
 import com.vitorpamplona.amethyst.commons.ui.loadStringRes
 import com.vitorpamplona.amethyst.commons.ui.navigation.navs.INav
@@ -92,7 +92,8 @@ fun EditGroupInfoScreen(
     var removeIcon by remember { mutableStateOf(false) }
     var isSaving by remember { mutableStateOf(false) }
     val scope = rememberCoroutineScope()
-    val context = LocalContext.current
+    val shortNotice = rememberShortNotice()
+    val longNotice = rememberLongNotice()
 
     val iconChanged = pickedIcon != null || removeIcon
     val avatarUrlChanged = avatarUrl.trim() != currentAvatarUrl?.url.orEmpty()
@@ -136,20 +137,13 @@ fun EditGroupInfoScreen(
                                 accountViewModel.setMarmotGroupAvatarUrl(nostrGroupId, avatarUrl.trim())
                             }
                             launch(Dispatchers.Main) {
-                                Toast
-                                    .makeText(context, loadStringRes(Res.string.marmot_group_info_updated), Toast.LENGTH_SHORT)
-                                    .show()
+                                shortNotice.show(loadStringRes(Res.string.marmot_group_info_updated))
                             }
                             nav.popBack()
                         } catch (e: Exception) {
                             isSaving = false
                             launch(Dispatchers.Main) {
-                                Toast
-                                    .makeText(
-                                        context,
-                                        loadStringRes(Res.string.marmot_failed_to_update, e.message),
-                                        Toast.LENGTH_LONG,
-                                    ).show()
+                                longNotice.show(loadStringRes(Res.string.marmot_failed_to_update, e.message))
                             }
                         }
                     }

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/VoiceReplyViewModel.kt

@@ -220,7 +220,7 @@ class VoiceReplyViewModel : ViewModel() {
                         loadStringRes(Res.string.upload_error_title),
                         loadStringRes(
                             Res.string.upload_error_voice_message_exception,
-                            e.message ?: e.javaClass.simpleName,
+                            e.message ?: e::class.simpleName.orEmpty(),
                         ),
                     )
                 } finally {

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/home/live/RenderLiveActivityBubble.kt

@@ -29,7 +29,6 @@ import androidx.compose.runtime.getValue
 import androidx.compose.runtime.remember
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.dp
 import com.vitorpamplona.amethyst.commons.model.cache.LocalCache
 import com.vitorpamplona.amethyst.commons.model.navigation.routeFor
@@ -39,9 +38,9 @@ import com.vitorpamplona.amethyst.commons.relayClient.reqCommand.channel.observe
 import com.vitorpamplona.amethyst.commons.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.commons.ui.navigation.routes.routeFor
 import com.vitorpamplona.amethyst.commons.ui.note.Gallery
+import com.vitorpamplona.amethyst.commons.ui.platform.LocalAppPlatform
 import com.vitorpamplona.amethyst.commons.ui.theme.StdHorzSpacer
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
-import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.activity.NestActivity
 import com.vitorpamplona.quartz.nip53LiveActivities.meetingSpaces.MeetingSpaceEvent
 
 @Composable
@@ -65,7 +64,7 @@ fun RenderLiveActivityBubble(
                 null
             }
         }
-    val context = LocalContext.current
+    val appPlatform = LocalAppPlatform.current
     FilledTonalButton(
         contentPadding = PaddingValues(start = 8.dp, end = 10.dp, bottom = 0.dp, top = 0.dp),
         onClick = {
@@ -75,10 +74,7 @@ fun RenderLiveActivityBubble(
                 val dTag = meetingEvent.address().dTag
                 if (!service.isNullOrBlank() && !endpoint.isNullOrBlank() && dTag.isNotBlank()) {
                     NestBridge.set(accountViewModel)
-                    NestActivity.launch(
-                        context = context,
-                        addressValue = meetingEvent.address().toValue(),
-                    )
+                    appPlatform.openNestRoom(meetingEvent.address().toValue())
                 } else {
                     // Fall back to the channel route so the user
                     // still lands somewhere — same as a malformed

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/nests/room/lobby/NestLobbyScreen.kt

@@ -55,7 +55,6 @@ import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.layout.ContentScale
-import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
 import androidx.lifecycle.viewmodel.compose.viewModel
@@ -85,11 +84,11 @@ import com.vitorpamplona.amethyst.commons.ui.note.types.MeetingSpaceClosedFlag
 import com.vitorpamplona.amethyst.commons.ui.note.types.MeetingSpaceOpenFlag
 import com.vitorpamplona.amethyst.commons.ui.note.types.MeetingSpacePlannedFlag
 import com.vitorpamplona.amethyst.commons.ui.note.types.MeetingSpacePrivateFlag
+import com.vitorpamplona.amethyst.commons.ui.platform.LocalAppPlatform
 import com.vitorpamplona.amethyst.commons.ui.screen.loggedIn.chats.feed.ChatroomMessageCompose
 import com.vitorpamplona.amethyst.commons.ui.stringRes
 import com.vitorpamplona.amethyst.commons.ui.theme.StdHorzSpacer
 import com.vitorpamplona.amethyst.commons.viewmodels.AccountViewModel
-import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.activity.NestActivity
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.chat.NestEditFieldRow
 import com.vitorpamplona.amethyst.ui.screen.loggedIn.nests.room.chat.NestNewMessageViewModel
 import com.vitorpamplona.quartz.nip01Core.core.Address
@@ -292,7 +291,7 @@ private fun OpenNestRoomAction(
     val roomId = event.address().dTag
     if (serviceBase.isNullOrBlank() || endpoint.isNullOrBlank() || roomId.isBlank()) return
 
-    val context = LocalContext.current
+    val appPlatform = LocalAppPlatform.current
     // Filled button so the primary CTA is unmistakable; the actions
     // Row in the AppBar already centers its children vertically, but
     // we trim the default end padding so the button sits flush with
@@ -300,10 +299,7 @@ private fun OpenNestRoomAction(
     Button(
         onClick = {
             NestBridge.set(accountViewModel)
-            NestActivity.launch(
-                context = context,
-                addressValue = event.address().toValue(),
-            )
+            appPlatform.openNestRoom(event.address().toValue())
         },
         contentPadding = ButtonDefaults.ContentPadding,
         modifier = Modifier.padding(end = 8.dp),

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/nip52Calendar/IcsExport.kt

@@ -20,14 +20,11 @@
  */
 package com.vitorpamplona.amethyst.commons.model.nip52Calendar
 
+import com.vitorpamplona.amethyst.commons.search.calendar.SearchDate
 import com.vitorpamplona.quartz.nip01Core.core.Address
 import com.vitorpamplona.quartz.nip52Calendar.appt.day.CalendarDateSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.appt.time.CalendarTimeSlotEvent
 import com.vitorpamplona.quartz.nip52Calendar.calendar.CalendarCollectionEvent
-import java.time.Instant
-import java.time.LocalDate
-import java.time.ZoneOffset
-import java.time.format.DateTimeFormatter
 
 /**
  * Serialises NIP-52 calendar events to RFC 5545 iCalendar (`.ics`) text. The output is the
@@ -47,8 +44,6 @@ import java.time.format.DateTimeFormatter
 object IcsExport {
     private const val PRODID = "-//Amethyst//NIP-52//EN"
     private const val CRLF = "\r\n"
-    private val UtcStamp: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss'Z'")
-    private val IsoBasicDate: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyyMMdd")
 
     fun appointmentToIcs(
         event: Any,
@@ -189,14 +184,21 @@ object IcsExport {
         sb.append("CATEGORIES:").append(hashtags.joinToString(",") { escapeText(it) }).append(CRLF)
     }
 
-    private fun formatUtcInstant(unixSeconds: Long): String = UtcStamp.format(Instant.ofEpochSecond(unixSeconds).atOffset(ZoneOffset.UTC))
+    /** `yyyyMMdd'T'HHmmss'Z'` in UTC. */
+    private fun formatUtcInstant(unixSeconds: Long): String {
+        val date = SearchDate.civilFromDays(unixSeconds.floorDiv(SECONDS_PER_DAY))
+        val secondOfDay = unixSeconds.mod(SECONDS_PER_DAY)
+        return basicDate(date) + "T" + pad2(secondOfDay / 3600) + pad2(secondOfDay / 60 % 60) + pad2(secondOfDay % 60) + "Z"
+    }
 
-    private fun tryFormatBasicDate(iso: String): String? =
-        try {
-            IsoBasicDate.format(LocalDate.parse(iso))
-        } catch (_: Throwable) {
-            null
-        }
+    /** `yyyy-MM-dd` as `yyyyMMdd`, or null when [iso] is not a valid date. */
+    private fun tryFormatBasicDate(iso: String): String? = SearchDate.parse(iso)?.let(::basicDate)
+
+    private fun basicDate(date: SearchDate): String = date.year.toString().padStart(4, '0') + pad2(date.month.toLong()) + pad2(date.day.toLong())
+
+    private fun pad2(value: Long): String = value.toString().padStart(2, '0')
+
+    private const val SECONDS_PER_DAY = 86_400L
 
     /**
      * Escapes text per RFC 5545 §3.3.11: backslash, semicolon, comma, newline. Carriage

commonsUI/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/ui/platform/AppPlatform.kt

@@ -111,6 +111,12 @@ interface AppPlatform {
     @Composable
     fun rememberWebAppIconModel(url: String): String? = null
 
+    /**
+     * Opens the audio room at [addressValue] (a kind-30312 address) in its own window; callers
+     * hand the account over through `NestBridge` first. Does nothing where rooms are not wired.
+     */
+    fun openNestRoom(addressValue: String) {}
+
     /** Draws nothing: previews, and front ends still wiring their pieces. */
     object None : AppPlatform
 }