feat(emoji): add public/private toggle to add emoji dialog

Adds a FilterChip toggle to AddEmojiDialog letting users choose whether a
new custom emoji is written to the public `emoji` tags or to the encrypted
`.content` (NIP-51 private tags) of their kind 30030 EmojiPackEvent.

Because the downstream consumers (`:` autocomplete via EmojiSuggestionState
and the reaction menu via RenderEmojiPack) currently read public tags only
through EmojiPackState.mergePack / EmojiPackEvent.taggedEmojis(), private
emojis are NOT surfaced end-to-end yet. Rather than silently shipping a
half-broken surface (which would also only work for self-owned packs since
foreign packs cannot be decrypted anyway), the dialog now shows an honest
explainer describing exactly what "private" means today: stored encrypted,
visible only to the pack owner in this screen.

EmojiPackScreen already rendered both lists; the grid now distinguishes
private entries with a small lock badge overlay and updates the
long-press deletion path to pass isPrivate through so removeEmoji removes
from the correct location (encrypted content vs public tags).

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/emojipacks/display/AddEmojiDialog.kt

@@ -24,8 +24,14 @@ import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
 import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Lock
+import androidx.compose.material.icons.filled.LockOpen
 import androidx.compose.material3.AlertDialog
 import androidx.compose.material3.Button
+import androidx.compose.material3.FilterChip
+import androidx.compose.material3.Icon
+import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
@@ -41,14 +47,28 @@ import com.vitorpamplona.amethyst.ui.theme.DoubleVertSpacer
 import com.vitorpamplona.quartz.nip01Core.core.Address
 import com.vitorpamplona.quartz.nip30CustomEmoji.EmojiUrlTag
 
+/**
+ * Dialog for adding a custom emoji to an owned emoji pack (NIP-30 kind 30030).
+ *
+ * The [onConfirm] callback receives the new [EmojiUrlTag] alongside an `isPrivate`
+ * flag: when `true`, the caller is expected to store the entry in the event's
+ * encrypted `.content` (NIP-51 private tags) rather than as a public tag.
+ *
+ * NOTE: Private emojis are currently only visible to the pack owner when viewing
+ * their own pack here. They are NOT surfaced in the reaction menu or in the `:`
+ * autocomplete picker, because those consumers read public tags only via
+ * [com.vitorpamplona.amethyst.commons.model.nip30CustomEmojis.EmojiPackState.mergePack].
+ * The dialog surfaces a warning so users understand the tradeoff.
+ */
 @Composable
 fun AddEmojiDialog(
     onDismiss: () -> Unit,
-    onConfirm: (EmojiUrlTag) -> Unit,
+    onConfirm: (EmojiUrlTag, Boolean) -> Unit,
 ) {
     var shortcode by remember { mutableStateOf("") }
     var url by remember { mutableStateOf("") }
     var packAddressText by remember { mutableStateOf("") }
+    var isPrivate by remember { mutableStateOf(false) }
 
     val shortcodeValid by remember {
         derivedStateOf {
@@ -101,6 +121,31 @@ fun AddEmojiDialog(
                     onValueChange = { packAddressText = it },
                     label = { Text(stringRes(R.string.emoji_pack_address_label)) },
                 )
+                Spacer(DoubleVertSpacer)
+                FilterChip(
+                    selected = isPrivate,
+                    onClick = { isPrivate = !isPrivate },
+                    label = { Text(stringRes(R.string.emoji_private_toggle)) },
+                    leadingIcon = {
+                        Icon(
+                            imageVector = if (isPrivate) Icons.Default.Lock else Icons.Default.LockOpen,
+                            contentDescription = null,
+                        )
+                    },
+                )
+                Spacer(DoubleVertSpacer)
+                Text(
+                    text =
+                        stringRes(
+                            if (isPrivate) {
+                                R.string.emoji_private_explainer
+                            } else {
+                                R.string.emoji_public_explainer
+                            },
+                        ),
+                    style = MaterialTheme.typography.bodySmall,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
             }
         },
         confirmButton = {
@@ -108,7 +153,10 @@ fun AddEmojiDialog(
                 enabled = canConfirm,
                 onClick = {
                     val parsedAddress = packAddressText.trim().takeIf { it.isNotEmpty() }?.let { Address.parse(it) }
-                    onConfirm(EmojiUrlTag(code = shortcode, url = url.trim(), emojiSet = parsedAddress))
+                    onConfirm(
+                        EmojiUrlTag(code = shortcode, url = url.trim(), emojiSet = parsedAddress),
+                        isPrivate,
+                    )
                 },
             ) {
                 Text(stringRes(R.string.add))

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/emojipacks/display/EmojiPackScreen.kt

@@ -21,6 +21,7 @@
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.emojipacks.display
 
 import androidx.compose.foundation.ExperimentalFoundationApi
+import androidx.compose.foundation.background
 import androidx.compose.foundation.combinedClickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -28,11 +29,13 @@ import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.consumeWindowInsets
 import androidx.compose.foundation.layout.fillMaxSize
 import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.lazy.grid.GridCells
 import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
 import androidx.compose.foundation.lazy.grid.items
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Lock
 import androidx.compose.material.icons.outlined.Add
 import androidx.compose.material3.ExtendedFloatingActionButton
 import androidx.compose.material3.Icon
@@ -49,6 +52,8 @@ import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.draw.clip
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.layout.ContentScale
 import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.unit.dp
@@ -90,7 +95,6 @@ private fun EmojiPackScreenView(
 ) {
     val pack by viewModel.selectedPackFlow.collectAsStateWithLifecycle()
     var showAddDialog by remember { mutableStateOf(false) }
-    var isAddingPrivate by remember { mutableStateOf(false) }
     var pendingDelete by remember { mutableStateOf<EmojiDeleteTarget?>(null) }
 
     Scaffold(
@@ -138,10 +142,7 @@ private fun EmojiPackScreenView(
                         contentDescription = null,
                     )
                 },
-                onClick = {
-                    isAddingPrivate = false
-                    showAddDialog = true
-                },
+                onClick = { showAddDialog = true },
                 shape = CircleShape,
                 containerColor = MaterialTheme.colorScheme.primary,
             )
@@ -168,9 +169,9 @@ private fun EmojiPackScreenView(
     if (showAddDialog) {
         AddEmojiDialog(
             onDismiss = { showAddDialog = false },
-            onConfirm = { tag ->
+            onConfirm = { tag, isPrivate ->
                 accountViewModel.launchSigner {
-                    viewModel.addEmoji(tag, isAddingPrivate)
+                    viewModel.addEmoji(tag, isPrivate)
                 }
                 showAddDialog = false
             },
@@ -189,6 +190,9 @@ private fun EmojiPackScreenView(
                     isDestructive = true,
                 ) {
                     accountViewModel.launchSigner {
+                        // removeEmoji must be called with the matching isPrivate flag
+                        // so we remove from the encrypted `.content` rather than the
+                        // public tag array (or vice-versa).
                         viewModel.removeEmoji(target.emoji.code, target.isPrivate)
                     }
                     pendingDelete = null
@@ -223,20 +227,53 @@ private fun EmojiGrid(
         horizontalArrangement = Arrangement.spacedBy(4.dp),
     ) {
         items(allEmojis, key = { (emoji, isPrivate) -> "${emoji.code}-${if (isPrivate) "priv" else "pub"}" }) { (emoji, isPrivate) ->
+            EmojiCell(
+                emoji = emoji,
+                isPrivate = isPrivate,
+                onLongClick = { onLongPress(emoji, isPrivate) },
+            )
+        }
+    }
+}
+
+@OptIn(ExperimentalFoundationApi::class)
+@Composable
+private fun EmojiCell(
+    emoji: EmojiUrlTag,
+    isPrivate: Boolean,
+    onLongClick: () -> Unit,
+) {
+    val privateLabel = stringRes(R.string.emoji_private_badge)
+    Box(
+        modifier =
+            Modifier
+                .combinedClickable(
+                    onClick = {},
+                    onLongClick = onLongClick,
+                ),
+        contentAlignment = Alignment.Center,
+    ) {
+        AsyncImage(
+            model = emoji.url,
+            contentDescription = if (isPrivate) "${emoji.code} ($privateLabel)" else emoji.code,
+            modifier = Size35Modifier,
+            contentScale = ContentScale.Crop,
+        )
+        if (isPrivate) {
             Box(
                 modifier =
                     Modifier
-                        .combinedClickable(
-                            onClick = {},
-                            onLongClick = { onLongPress(emoji, isPrivate) },
-                        ),
+                        .align(Alignment.TopEnd)
+                        .size(14.dp)
+                        .clip(CircleShape)
+                        .background(Color.Black.copy(alpha = 0.55f)),
                 contentAlignment = Alignment.Center,
             ) {
-                AsyncImage(
-                    model = emoji.url,
-                    contentDescription = emoji.code,
-                    modifier = Size35Modifier,
-                    contentScale = ContentScale.Crop,
+                Icon(
+                    imageVector = Icons.Filled.Lock,
+                    contentDescription = privateLabel,
+                    tint = Color.White,
+                    modifier = Modifier.size(10.dp),
                 )
             }
         }

amethyst/src/main/res/values/strings.xml

@@ -2398,4 +2398,8 @@
     <string name="emoji_pack_is_not_in_list">\"%1$s\" is not in your emoji list</string>
     <string name="emoji_pack_actions_dialog_title">Emoji pack actions</string>
     <string name="manage_emoji_packs">Manage Emoji Packs</string>
+    <string name="emoji_private_toggle">Private</string>
+    <string name="emoji_private_badge">Private emoji</string>
+    <string name="emoji_public_explainer">Public emojis appear in your reaction menu and in the \":\" autocomplete picker when this pack is in your emoji list.</string>
+    <string name="emoji_private_explainer">Private emojis are stored encrypted in your event content and are only visible to you here. They are NOT surfaced in the reaction menu or the \":\" autocomplete picker yet.</string>
 </resources>