feat: add profile picture upload button when user has no picture

When a user visits their own profile and has no profile picture set,
show a semi-transparent upload button overlay directly on the profile
picture area. Tapping it opens the gallery picker, uploads the image
to the configured server (NIP-96 or Blossom), and immediately saves
the metadata — without requiring the user to navigate to the edit screen.

- Add uploadPictureAndSave() to NewUserMetadataViewModel: loads current
  metadata, uploads the image, then saves all metadata with the new picture
- Add ProfilePictureWithUploadOverlay composable that wraps ZoomableUserPicture
  and conditionally shows the upload overlay when isMe && no picture
- Add ProfilePictureUploadButton composable for the overlay UI with
  loading state support
- Use ProfilePictureWithUploadOverlay in ProfileHeader instead of
  ZoomableUserPicture directly

https://claude.ai/code/session_01XemJ8Hx9q4mMd1StZNY9CE

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/actions/NewUserMetadataViewModel.kt

@@ -169,6 +169,26 @@ class NewUserMetadataViewModel : ViewModel() {
         }
     }
 
+    fun uploadPictureAndSave(
+        uri: SelectedMedia,
+        context: Context,
+        onError: (String, String) -> Unit,
+    ) {
+        load()
+        accountViewModel.launchSigner {
+            upload(
+                uri,
+                context,
+                onUploading = { isUploadingImageForPicture = it },
+                onUploaded = {
+                    picture.value = it
+                    create()
+                },
+                onError = onError,
+            )
+        }
+    }
+
     private suspend fun upload(
         galleryUri: SelectedMedia,
         context: Context,

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/screen/loggedIn/profile/header/ProfileHeader.kt

@@ -21,6 +21,8 @@
 package com.vitorpamplona.amethyst.ui.screen.loggedIn.profile.header
 
 import android.content.ClipData
+import androidx.compose.foundation.background
+import androidx.compose.foundation.clickable
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
@@ -30,7 +32,9 @@ import androidx.compose.foundation.layout.height
 import androidx.compose.foundation.layout.padding
 import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.statusBarsPadding
+import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.AddPhotoAlternate
 import androidx.compose.material.icons.filled.MoreVert
 import androidx.compose.material3.Button
 import androidx.compose.material3.ButtonDefaults
@@ -38,6 +42,7 @@ import androidx.compose.material3.HorizontalDivider
 import androidx.compose.material3.Icon
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.derivedStateOf
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
@@ -45,13 +50,20 @@ import androidx.compose.runtime.rememberCoroutineScope
 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.platform.ClipEntry
 import androidx.compose.ui.platform.LocalClipboard
+import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.unit.Dp
 import androidx.compose.ui.unit.dp
+import androidx.lifecycle.viewmodel.compose.viewModel
 import com.vitorpamplona.amethyst.R
 import com.vitorpamplona.amethyst.commons.richtext.RichTextParser
 import com.vitorpamplona.amethyst.model.User
+import com.vitorpamplona.amethyst.service.relayClient.reqCommand.user.observeUserPicture
+import com.vitorpamplona.amethyst.ui.actions.NewUserMetadataViewModel
+import com.vitorpamplona.amethyst.ui.actions.uploads.GallerySelectSingle
+import com.vitorpamplona.amethyst.ui.components.LoadingAnimation
 import com.vitorpamplona.amethyst.ui.components.ZoomableImageDialog
 import com.vitorpamplona.amethyst.ui.navigation.navs.INav
 import com.vitorpamplona.amethyst.ui.note.ClickableUserPicture
@@ -126,7 +138,7 @@ fun ProfileHeader(
                 horizontalArrangement = Arrangement.SpaceBetween,
                 verticalAlignment = Alignment.Bottom,
             ) {
-                ZoomableUserPicture(
+                ProfilePictureWithUploadOverlay(
                     baseUser = baseUser,
                     accountViewModel = accountViewModel,
                     size = Size100dp,
@@ -189,3 +201,76 @@ fun ZoomableUserPicture(
         )
     }
 }
+
+@Composable
+fun ProfilePictureWithUploadOverlay(
+    baseUser: User,
+    accountViewModel: AccountViewModel,
+    size: Dp,
+) {
+    val isMe by remember(accountViewModel) { derivedStateOf { accountViewModel.userProfile() == baseUser } }
+    val picture by observeUserPicture(baseUser, accountViewModel)
+
+    Box(contentAlignment = Alignment.Center) {
+        ZoomableUserPicture(
+            baseUser = baseUser,
+            accountViewModel = accountViewModel,
+            size = size,
+        )
+        if (isMe && picture.isNullOrBlank()) {
+            ProfilePictureUploadButton(accountViewModel, size)
+        }
+    }
+}
+
+@Composable
+private fun ProfilePictureUploadButton(
+    accountViewModel: AccountViewModel,
+    size: Dp,
+) {
+    val postViewModel: NewUserMetadataViewModel = viewModel()
+    postViewModel.init(accountViewModel)
+    val context = LocalContext.current
+
+    var showGallerySelect by remember { mutableStateOf(false) }
+    if (showGallerySelect) {
+        GallerySelectSingle(
+            onImageUri = { media ->
+                showGallerySelect = false
+                if (media != null) {
+                    postViewModel.uploadPictureAndSave(media, context, accountViewModel.toastManager::toast)
+                }
+            },
+        )
+    }
+
+    if (postViewModel.isUploadingImageForPicture) {
+        Box(
+            modifier =
+                Modifier
+                    .size(size)
+                    .clip(CircleShape)
+                    .background(MaterialTheme.colorScheme.surface.copy(alpha = 0.7f)),
+            contentAlignment = Alignment.Center,
+        ) {
+            LoadingAnimation()
+        }
+    } else {
+        Box(
+            modifier =
+                Modifier
+                    .size(size)
+                    .clip(CircleShape)
+                    .background(MaterialTheme.colorScheme.surface.copy(alpha = 0.7f))
+                    .clickable { showGallerySelect = true },
+            contentAlignment = Alignment.Center,
+        ) {
+            Icon(
+                imageVector = Icons.Default.AddPhotoAlternate,
+                contentDescription = stringRes(R.string.upload_image),
+                modifier = Modifier.size(40.dp),
+                tint = MaterialTheme.colorScheme.onSurface,
+            )
+        }
+    }
+}