feat(highlights): add article highlights and note-taking system

Phase 1: HighlightData model + DesktopHighlightStore (Preferences-based)
Phase 2: Text selection highlight via Cmd+H/Cmd+Shift+H, inline bold/italic
         rendering, HighlightAnnotationDialog, SelectionContainer wrapping
Phase 3: MyHighlightsScreen with grouped view, HighlightPublishAction for
         NIP-84 (kind 9802), deck/sidebar/menu wiring

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/compose/markdown/RenderMarkdown.kt

@@ -42,10 +42,27 @@ fun RenderMarkdown(
     onLinkClick: (String) -> Unit,
     modifier: Modifier = Modifier,
     fontScale: Float = 1.0f,
+    highlightedTexts: List<String> = emptyList(),
 ) {
+    val processedContent =
+        remember(content, highlightedTexts) {
+            if (highlightedTexts.isEmpty()) {
+                content
+            } else {
+                var result = content
+                highlightedTexts.sortedByDescending { it.length }.forEach { text ->
+                    val idx = result.indexOf(text)
+                    if (idx >= 0) {
+                        result = result.replaceFirst(text, "***$text***")
+                    }
+                }
+                result
+            }
+        }
+
     val astNode =
-        remember(content) {
+        remember(processedContent) {
-            CommonmarkAstNodeParser(CommonMarkdownParseOptions.MarkdownWithLinks).parse(content)
+            CommonmarkAstNodeParser(CommonMarkdownParseOptions.MarkdownWithLinks).parse(processedContent)
         }
 
     val uriHandler =

commons/src/commonMain/kotlin/com/vitorpamplona/amethyst/commons/model/highlights/HighlightData.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.commons.model.highlights
+
+data class HighlightData(
+    val id: String,
+    val text: String,
+    val note: String? = null,
+    val articleAddressTag: String,
+    val articleTitle: String? = null,
+    val createdAt: Long,
+    val published: Boolean = false,
+    val eventId: String? = null,
+)

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/Main.kt

@@ -380,6 +380,7 @@ fun main() {
                             Item("Search", onClick = { deckState.addColumn(DeckColumnType.Search) })
                             Item("Reads", onClick = { deckState.addColumn(DeckColumnType.Reads) })
                             Item("Drafts", onClick = { deckState.addColumn(DeckColumnType.Drafts) })
+                            Item("Highlights", onClick = { deckState.addColumn(DeckColumnType.MyHighlights) })
                             Item("Bookmarks", onClick = { deckState.addColumn(DeckColumnType.Bookmarks) })
                             Item("Global Feed", onClick = { deckState.addColumn(DeckColumnType.GlobalFeed) })
                             Item("Profile", onClick = { deckState.addColumn(DeckColumnType.MyProfile) })

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/service/highlights/DesktopHighlightStore.kt

@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.desktop.service.highlights
+
+import com.fasterxml.jackson.module.kotlin.jacksonObjectMapper
+import com.fasterxml.jackson.module.kotlin.readValue
+import com.vitorpamplona.amethyst.commons.model.highlights.HighlightData
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.StandardCopyOption
+import java.time.Instant
+import java.util.UUID
+
+/**
+ * Local highlight storage for article annotations.
+ * Stores highlights as JSON in ~/.amethyst/highlights/index.json.
+ * Uses atomic writes following the same pattern as DesktopDraftStore.
+ */
+class DesktopHighlightStore(
+    private val scope: CoroutineScope,
+) {
+    private val mapper = jacksonObjectMapper()
+    private val mutex = Mutex()
+
+    private val _highlights = MutableStateFlow<Map<String, List<HighlightData>>>(emptyMap())
+    val highlights: StateFlow<Map<String, List<HighlightData>>> = _highlights.asStateFlow()
+
+    private val highlightsDir: File by lazy {
+        val dir = File(System.getProperty("user.home"), ".amethyst/highlights")
+        if (!dir.exists()) {
+            dir.mkdirs()
+        }
+        dir
+    }
+
+    private val indexFile: File get() = File(highlightsDir, "index.json")
+
+    init {
+        scope.launch(Dispatchers.IO) {
+            loadIndex()
+        }
+    }
+
+    suspend fun addHighlight(
+        articleAddressTag: String,
+        text: String,
+        note: String?,
+        articleTitle: String?,
+    ) {
+        mutex.withLock {
+            val current = _highlights.value.toMutableMap()
+            val articleHighlights = current.getOrDefault(articleAddressTag, emptyList()).toMutableList()
+
+            // Avoid duplicate highlights of the same text
+            if (articleHighlights.any { it.text == text }) return
+
+            articleHighlights.add(
+                HighlightData(
+                    id = UUID.randomUUID().toString(),
+                    text = text,
+                    note = note,
+                    articleAddressTag = articleAddressTag,
+                    articleTitle = articleTitle,
+                    createdAt = Instant.now().epochSecond,
+                ),
+            )
+            current[articleAddressTag] = articleHighlights
+            _highlights.value = current
+            saveIndex(current)
+        }
+    }
+
+    suspend fun updateNote(
+        highlightId: String,
+        note: String,
+    ) {
+        mutex.withLock {
+            val current = _highlights.value.toMutableMap()
+            for ((key, list) in current) {
+                val idx = list.indexOfFirst { it.id == highlightId }
+                if (idx >= 0) {
+                    current[key] =
+                        list.toMutableList().apply {
+                            set(idx, get(idx).copy(note = note))
+                        }
+                    _highlights.value = current
+                    saveIndex(current)
+                    return
+                }
+            }
+        }
+    }
+
+    suspend fun removeHighlight(highlightId: String) {
+        mutex.withLock {
+            val current = _highlights.value.toMutableMap()
+            for ((key, list) in current) {
+                val filtered = list.filter { it.id != highlightId }
+                if (filtered.size != list.size) {
+                    if (filtered.isEmpty()) {
+                        current.remove(key)
+                    } else {
+                        current[key] = filtered
+                    }
+                    _highlights.value = current
+                    saveIndex(current)
+                    return
+                }
+            }
+        }
+    }
+
+    suspend fun markPublished(
+        highlightId: String,
+        eventId: String,
+    ) {
+        mutex.withLock {
+            val current = _highlights.value.toMutableMap()
+            for ((key, list) in current) {
+                val idx = list.indexOfFirst { it.id == highlightId }
+                if (idx >= 0) {
+                    current[key] =
+                        list.toMutableList().apply {
+                            set(idx, get(idx).copy(published = true, eventId = eventId))
+                        }
+                    _highlights.value = current
+                    saveIndex(current)
+                    return
+                }
+            }
+        }
+    }
+
+    fun getHighlightsForArticle(addressTag: String): List<HighlightData> = _highlights.value[addressTag] ?: emptyList()
+
+    fun getAllHighlights(): Map<String, List<HighlightData>> = _highlights.value
+
+    private suspend fun loadIndex() {
+        mutex.withLock {
+            if (indexFile.exists()) {
+                try {
+                    val data: Map<String, List<HighlightData>> = mapper.readValue(indexFile)
+                    _highlights.value = data
+                } catch (e: Exception) {
+                    // Corrupted file — start fresh
+                    _highlights.value = emptyMap()
+                }
+            }
+        }
+    }
+
+    private fun saveIndex(data: Map<String, List<HighlightData>>) {
+        try {
+            val json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(data)
+            val tempFile = File(highlightsDir, "index.json.tmp")
+            tempFile.writeText(json)
+            Files.move(
+                tempFile.toPath(),
+                indexFile.toPath(),
+                StandardCopyOption.REPLACE_EXISTING,
+                StandardCopyOption.ATOMIC_MOVE,
+            )
+        } catch (_: Exception) {
+            // Best effort — don't crash on write failure
+        }
+    }
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/ArticleReaderScreen.kt

@@ -34,6 +34,7 @@ import androidx.compose.foundation.layout.size
 import androidx.compose.foundation.layout.width
 import androidx.compose.foundation.layout.widthIn
 import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.text.selection.SelectionContainer
 import androidx.compose.foundation.verticalScroll
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.filled.ArrowBack
@@ -49,6 +50,7 @@ import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -56,9 +58,11 @@ import androidx.compose.ui.focus.focusRequester
 import androidx.compose.ui.input.key.Key
 import androidx.compose.ui.input.key.KeyEventType
 import androidx.compose.ui.input.key.isMetaPressed
+import androidx.compose.ui.input.key.isShiftPressed
 import androidx.compose.ui.input.key.key
 import androidx.compose.ui.input.key.onPreviewKeyEvent
 import androidx.compose.ui.input.key.type
+import androidx.compose.ui.platform.LocalClipboardManager
 import androidx.compose.ui.unit.dp
 import com.vitorpamplona.amethyst.commons.compose.article.ArticleHeader
 import com.vitorpamplona.amethyst.commons.compose.article.TableOfContents
@@ -70,6 +74,7 @@ import com.vitorpamplona.amethyst.commons.ui.components.LoadingState
 import com.vitorpamplona.amethyst.desktop.account.AccountState
 import com.vitorpamplona.amethyst.desktop.cache.DesktopLocalCache
 import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
+import com.vitorpamplona.amethyst.desktop.service.highlights.DesktopHighlightStore
 import com.vitorpamplona.amethyst.desktop.subscriptions.DesktopRelaySubscriptionsCoordinator
 import com.vitorpamplona.amethyst.desktop.subscriptions.FilterBuilders
 import com.vitorpamplona.amethyst.desktop.subscriptions.SubscriptionConfig
@@ -78,12 +83,14 @@ import com.vitorpamplona.amethyst.desktop.subscriptions.createRepliesSubscriptio
 import com.vitorpamplona.amethyst.desktop.subscriptions.createRepostsSubscription
 import com.vitorpamplona.amethyst.desktop.subscriptions.createZapsSubscription
 import com.vitorpamplona.amethyst.desktop.subscriptions.rememberSubscription
+import com.vitorpamplona.amethyst.desktop.ui.highlights.HighlightAnnotationDialog
 import com.vitorpamplona.quartz.nip18Reposts.RepostEvent
 import com.vitorpamplona.quartz.nip23LongContent.LongTextNoteEvent
 import com.vitorpamplona.quartz.nip25Reactions.ReactionEvent
 import com.vitorpamplona.quartz.nip47WalletConnect.Nip47WalletConnect
 import com.vitorpamplona.quartz.nip51Lists.bookmarkList.BookmarkListEvent
 import com.vitorpamplona.quartz.nip57Zaps.LnZapEvent
+import kotlinx.coroutines.launch
 import java.time.Instant
 import java.time.ZoneId
 import java.time.format.DateTimeFormatter
@@ -115,6 +122,7 @@ fun ArticleReaderScreen(
     account: AccountState.LoggedIn?,
     nwcConnection: Nip47WalletConnect.Nip47URINorm? = null,
     subscriptionsCoordinator: DesktopRelaySubscriptionsCoordinator? = null,
+    highlightStore: DesktopHighlightStore? = null,
     onBack: () -> Unit,
     onNavigateToProfile: (String) -> Unit = {},
     onNavigateToThread: (String) -> Unit = {},
@@ -135,6 +143,18 @@ fun ArticleReaderScreen(
 
     // Zoom level for article text
     var zoomLevel by remember { mutableStateOf(1.0f) }
+
+    // Coroutine scope for highlight operations
+    val scope = rememberCoroutineScope()
+
+    // Highlight state
+    val articleHighlights =
+        highlightStore?.let { store ->
+            val allHighlights by store.highlights.collectAsState()
+            allHighlights[addressTag] ?: emptyList()
+        } ?: emptyList()
+
+    var showAnnotationDialog by remember { mutableStateOf<String?>(null) }
     val focusRequester =
         remember {
             androidx.compose.ui.focus
@@ -331,6 +351,8 @@ fun ArticleReaderScreen(
     val authorName = authorUser?.toBestDisplayName()
     val authorPicture = authorUser?.profilePicture()
 
+    val clipboardManager = LocalClipboardManager.current
+
     LaunchedEffect(Unit) {
         focusRequester.requestFocus()
     }
@@ -359,6 +381,27 @@ fun ArticleReaderScreen(
                                 true
                             }
 
+                            Key.H -> {
+                                val selectedText = clipboardManager.getText()?.text
+                                if (!selectedText.isNullOrBlank() && highlightStore != null) {
+                                    if (event.isShiftPressed) {
+                                        showAnnotationDialog = selectedText
+                                    } else {
+                                        scope.launch {
+                                            highlightStore.addHighlight(
+                                                articleAddressTag = addressTag,
+                                                text = selectedText,
+                                                note = null,
+                                                articleTitle = title,
+                                            )
+                                        }
+                                    }
+                                    true
+                                } else {
+                                    false
+                                }
+                            }
+
                             else -> {
                                 false
                             }
@@ -480,12 +523,15 @@ fun ArticleReaderScreen(
                                     thickness = 1.dp,
                                 )
 
-                                // Markdown body
+                                // Markdown body with selectable text
+                                SelectionContainer {
                                     RenderMarkdown(
                                         content = content,
                                         onLinkClick = onLinkClick,
                                         fontScale = zoomLevel,
+                                        highlightedTexts = articleHighlights.map { it.text },
                                     )
+                                }
 
                                 Spacer(Modifier.height(32.dp))
 
@@ -549,4 +595,22 @@ fun ArticleReaderScreen(
             }
         }
     }
+
+    showAnnotationDialog?.let { selectedText ->
+        HighlightAnnotationDialog(
+            selectedText = selectedText,
+            onConfirm = { note ->
+                scope.launch {
+                    highlightStore?.addHighlight(
+                        articleAddressTag = addressTag,
+                        text = selectedText,
+                        note = note,
+                        articleTitle = title,
+                    )
+                }
+                showAnnotationDialog = null
+            },
+            onDismiss = { showAnnotationDialog = null },
+        )
+    }
 }

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/deck/AddColumnDialog.kt

@@ -54,6 +54,7 @@ private val COLUMN_OPTIONS =
         DeckColumnType.Search,
         DeckColumnType.Reads,
         DeckColumnType.Drafts,
+        DeckColumnType.MyHighlights,
         DeckColumnType.Bookmarks,
         DeckColumnType.GlobalFeed,
         DeckColumnType.MyProfile,

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/deck/ColumnHeader.kt

@@ -135,6 +135,7 @@ fun DeckColumnType.icon(): ImageVector =
         is DeckColumnType.Article -> Icons.AutoMirrored.Filled.Article
         is DeckColumnType.Editor -> Icons.AutoMirrored.Filled.Article
         DeckColumnType.Drafts -> Icons.AutoMirrored.Filled.Article
+        DeckColumnType.MyHighlights -> Icons.AutoMirrored.Filled.Article
         is DeckColumnType.Profile -> Icons.Default.Person
         is DeckColumnType.Thread -> Icons.AutoMirrored.Filled.Article
         is DeckColumnType.Hashtag -> Icons.Default.Tag

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/deck/DeckColumnContainer.kt

@@ -45,6 +45,7 @@ import com.vitorpamplona.amethyst.desktop.chess.ChessScreen
 import com.vitorpamplona.amethyst.desktop.model.DesktopIAccount
 import com.vitorpamplona.amethyst.desktop.network.DesktopRelayConnectionManager
 import com.vitorpamplona.amethyst.desktop.service.drafts.DesktopDraftStore
+import com.vitorpamplona.amethyst.desktop.service.highlights.DesktopHighlightStore
 import com.vitorpamplona.amethyst.desktop.subscriptions.DesktopRelaySubscriptionsCoordinator
 import com.vitorpamplona.amethyst.desktop.subscriptions.FeedMode
 import com.vitorpamplona.amethyst.desktop.ui.ArticleEditorScreen
@@ -105,6 +106,8 @@ fun DeckColumnContainer(
     val navState = remember(column.id) { ColumnNavigationState() }
     val navStack by navState.stack.collectAsState()
     val currentOverlay = navStack.lastOrNull()
+    val containerScope = rememberCoroutineScope()
+    val highlightStore = remember { DesktopHighlightStore(containerScope) }
 
     Column(
         modifier =
@@ -136,6 +139,7 @@ fun DeckColumnContainer(
                 iAccount = iAccount,
                 nwcConnection = nwcConnection,
                 subscriptionsCoordinator = subscriptionsCoordinator,
+                highlightStore = highlightStore,
                 appScope = appScope,
                 compactMode = true,
                 onShowComposeDialog = onShowComposeDialog,
@@ -157,6 +161,7 @@ fun DeckColumnContainer(
                         account = account,
                         nwcConnection = nwcConnection,
                         subscriptionsCoordinator = subscriptionsCoordinator,
+                        highlightStore = highlightStore,
                         onShowComposeDialog = onShowComposeDialog,
                         onShowReplyDialog = onShowReplyDialog,
                         onZapFeedback = onZapFeedback,
@@ -180,6 +185,7 @@ internal fun RootContent(
     iAccount: DesktopIAccount,
     nwcConnection: Nip47URINorm?,
     subscriptionsCoordinator: DesktopRelaySubscriptionsCoordinator,
+    highlightStore: DesktopHighlightStore? = null,
     appScope: CoroutineScope,
     compactMode: Boolean = false,
     onShowComposeDialog: () -> Unit,
@@ -339,6 +345,7 @@ internal fun RootContent(
                 localCache = localCache,
                 account = account,
                 subscriptionsCoordinator = subscriptionsCoordinator,
+                highlightStore = highlightStore,
                 onBack = {},
                 onNavigateToProfile = onNavigateToProfile,
             )
@@ -364,6 +371,13 @@ internal fun RootContent(
             )
         }
 
+        DeckColumnType.MyHighlights -> {
+            com.vitorpamplona.amethyst.desktop.ui.highlights.MyHighlightsScreen(
+                highlightStore = highlightStore ?: remember { DesktopHighlightStore(scope) },
+                onNavigateToArticle = onNavigateToArticle,
+            )
+        }
+
         is DeckColumnType.Hashtag -> {
             SearchScreen(
                 localCache = localCache,
@@ -385,6 +399,7 @@ internal fun OverlayContent(
     account: AccountState.LoggedIn,
     nwcConnection: Nip47URINorm?,
     subscriptionsCoordinator: DesktopRelaySubscriptionsCoordinator,
+    highlightStore: DesktopHighlightStore? = null,
     onShowComposeDialog: () -> Unit,
     onShowReplyDialog: (com.vitorpamplona.quartz.nip01Core.core.Event) -> Unit,
     onZapFeedback: (ZapFeedback) -> Unit,
@@ -431,6 +446,7 @@ internal fun OverlayContent(
                 localCache = localCache,
                 account = account,
                 subscriptionsCoordinator = subscriptionsCoordinator,
+                highlightStore = highlightStore,
                 onBack = onBack,
                 onNavigateToProfile = onNavigateToProfile,
             )

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/deck/DeckColumnType.kt

@@ -61,6 +61,8 @@ sealed class DeckColumnType {
 
     object Drafts : DeckColumnType()
 
+    object MyHighlights : DeckColumnType()
+
     data class Hashtag(
         val tag: String,
     ) : DeckColumnType()
@@ -80,6 +82,7 @@ sealed class DeckColumnType {
             is Article -> "Article"
             is Editor -> "New Article"
             Drafts -> "Drafts"
+            MyHighlights -> "Highlights"
             is Profile -> "Profile"
             is Thread -> "Thread"
             is Hashtag -> "#$tag"
@@ -100,6 +103,7 @@ sealed class DeckColumnType {
             is Article -> "article"
             is Editor -> "editor"
             Drafts -> "drafts"
+            MyHighlights -> "highlights"
             is Profile -> "profile"
             is Thread -> "thread"
             is Hashtag -> "hashtag"

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/deck/SinglePaneLayout.kt

@@ -80,6 +80,7 @@ private val navItems =
         NavItem(DeckColumnType.HomeFeed, Icons.Default.Home, "Home"),
         NavItem(DeckColumnType.Reads, Icons.AutoMirrored.Filled.Article, "Reads"),
         NavItem(DeckColumnType.Drafts, Icons.AutoMirrored.Filled.Article, "Drafts"),
+        NavItem(DeckColumnType.MyHighlights, Icons.AutoMirrored.Filled.Article, "Highlights"),
         NavItem(DeckColumnType.Search, Icons.Default.Search, "Search"),
         NavItem(DeckColumnType.Bookmarks, Icons.Default.Bookmark, "Bookmarks"),
         NavItem(DeckColumnType.Messages, Icons.Default.Email, "Messages"),

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/highlights/HighlightAnnotationDialog.kt

@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.desktop.ui.highlights
+
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedTextField
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.unit.dp
+
+@Composable
+fun HighlightAnnotationDialog(
+    selectedText: String,
+    onConfirm: (note: String) -> Unit,
+    onDismiss: () -> Unit,
+) {
+    var note by remember { mutableStateOf("") }
+
+    AlertDialog(
+        onDismissRequest = onDismiss,
+        title = { Text("Add Highlight Note") },
+        text = {
+            Column {
+                Text(
+                    text = "\"$selectedText\"",
+                    style = MaterialTheme.typography.bodyMedium,
+                    color = MaterialTheme.colorScheme.onSurfaceVariant,
+                )
+                Spacer(Modifier.height(12.dp))
+                OutlinedTextField(
+                    value = note,
+                    onValueChange = { note = it },
+                    label = { Text("Note (optional)") },
+                    modifier = Modifier.fillMaxWidth(),
+                    minLines = 2,
+                    maxLines = 5,
+                )
+            }
+        },
+        confirmButton = {
+            TextButton(onClick = { onConfirm(note) }) {
+                Text("Save")
+            }
+        },
+        dismissButton = {
+            TextButton(onClick = onDismiss) {
+                Text("Cancel")
+            }
+        },
+    )
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/highlights/HighlightPublishAction.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.desktop.ui.highlights
+
+import com.vitorpamplona.quartz.nip01Core.signers.NostrSigner
+import com.vitorpamplona.quartz.nip01Core.tags.aTag.ATag
+import com.vitorpamplona.quartz.nip01Core.tags.people.PTag
+import com.vitorpamplona.quartz.nip31Alts.AltTag
+import com.vitorpamplona.quartz.nip84Highlights.HighlightEvent
+import com.vitorpamplona.quartz.nip84Highlights.tags.CommentTag
+import com.vitorpamplona.quartz.nip84Highlights.tags.ContextTag
+import com.vitorpamplona.quartz.utils.TimeUtils
+
+object HighlightPublishAction {
+    suspend fun publish(
+        highlightText: String,
+        articleAddressTag: String,
+        note: String?,
+        context: String?,
+        signer: NostrSigner,
+    ): HighlightEvent {
+        val tags = mutableListOf<Array<String>>()
+
+        tags.add(AltTag.assemble(HighlightEvent.ALT))
+        tags.add(ATag.assemble(articleAddressTag, null))
+
+        // Tag the article author
+        val parts = articleAddressTag.split(":", limit = 3)
+        val pubkey = parts.getOrNull(1)
+        if (!pubkey.isNullOrBlank()) {
+            tags.add(PTag.assemble(pubkey, null))
+        }
+
+        if (!note.isNullOrBlank()) {
+            tags.add(CommentTag.assemble(note))
+        }
+
+        if (!context.isNullOrBlank()) {
+            tags.add(ContextTag.assemble(context))
+        }
+
+        return signer.sign(
+            createdAt = TimeUtils.now(),
+            kind = HighlightEvent.KIND,
+            tags = tags.toTypedArray(),
+            content = highlightText,
+        )
+    }
+
+    fun extractContext(
+        content: String,
+        highlightText: String,
+    ): String? {
+        val paragraphs = content.split("\n\n")
+        return paragraphs.find { it.contains(highlightText) }
+    }
+}

desktopApp/src/jvmMain/kotlin/com/vitorpamplona/amethyst/desktop/ui/highlights/MyHighlightsScreen.kt

@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 2025 Vitor Pamplona
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to use,
+ * copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the
+ * Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package com.vitorpamplona.amethyst.desktop.ui.highlights
+
+import androidx.compose.foundation.clickable
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.lazy.LazyColumn
+import androidx.compose.foundation.lazy.items
+import androidx.compose.material.icons.Icons
+import androidx.compose.material.icons.filled.Delete
+import androidx.compose.material.icons.filled.Lock
+import androidx.compose.material.icons.filled.Public
+import androidx.compose.material3.AlertDialog
+import androidx.compose.material3.Card
+import androidx.compose.material3.CardDefaults
+import androidx.compose.material3.Icon
+import androidx.compose.material3.IconButton
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.rememberCoroutineScope
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import com.vitorpamplona.amethyst.commons.model.highlights.HighlightData
+import com.vitorpamplona.amethyst.commons.ui.components.EmptyState
+import com.vitorpamplona.amethyst.desktop.service.highlights.DesktopHighlightStore
+import kotlinx.coroutines.launch
+import java.time.Instant
+import java.time.ZoneId
+import java.time.format.DateTimeFormatter
+
+@Composable
+fun MyHighlightsScreen(
+    highlightStore: DesktopHighlightStore,
+    onNavigateToArticle: (addressTag: String) -> Unit,
+) {
+    val allHighlights by highlightStore.highlights.collectAsState()
+    val scope = rememberCoroutineScope()
+    var deleteTarget by remember { mutableStateOf<HighlightData?>(null) }
+
+    Column(modifier = Modifier.fillMaxSize()) {
+        Text(
+            "Highlights",
+            style = MaterialTheme.typography.headlineMedium,
+            color = MaterialTheme.colorScheme.onBackground,
+        )
+
+        Spacer(Modifier.height(16.dp))
+
+        if (allHighlights.isEmpty()) {
+            EmptyState(
+                title = "No highlights yet",
+                description = "Select text in an article and choose \"Highlight\" to save passages.",
+            )
+        } else {
+            LazyColumn(
+                verticalArrangement = Arrangement.spacedBy(8.dp),
+            ) {
+                allHighlights.forEach { (addressTag, highlights) ->
+                    val articleTitle = highlights.firstOrNull()?.articleTitle ?: addressTag
+
+                    stickyHeader(key = addressTag) {
+                        ArticleGroupHeader(
+                            title = articleTitle,
+                            onClick = { onNavigateToArticle(addressTag) },
+                        )
+                    }
+
+                    items(highlights, key = { it.id }) { highlight ->
+                        HighlightCard(
+                            highlight = highlight,
+                            onDelete = { deleteTarget = highlight },
+                        )
+                    }
+                }
+            }
+        }
+    }
+
+    deleteTarget?.let { highlight ->
+        AlertDialog(
+            onDismissRequest = { deleteTarget = null },
+            title = { Text("Delete Highlight") },
+            text = {
+                Text(
+                    "Delete this highlight? This cannot be undone.",
+                )
+            },
+            confirmButton = {
+                TextButton(onClick = {
+                    scope.launch { highlightStore.removeHighlight(highlight.id) }
+                    deleteTarget = null
+                }) {
+                    Text("Delete", color = MaterialTheme.colorScheme.error)
+                }
+            },
+            dismissButton = {
+                TextButton(onClick = { deleteTarget = null }) {
+                    Text("Cancel")
+                }
+            },
+        )
+    }
+}
+
+@Composable
+private fun ArticleGroupHeader(
+    title: String,
+    onClick: () -> Unit,
+) {
+    Row(
+        modifier =
+            Modifier
+                .fillMaxWidth()
+                .clickable(onClick = onClick)
+                .padding(vertical = 8.dp),
+        verticalAlignment = Alignment.CenterVertically,
+    ) {
+        Text(
+            text = title,
+            style = MaterialTheme.typography.titleMedium,
+            color = MaterialTheme.colorScheme.primary,
+            maxLines = 1,
+            overflow = TextOverflow.Ellipsis,
+        )
+    }
+}
+
+@Composable
+private fun HighlightCard(
+    highlight: HighlightData,
+    onDelete: () -> Unit,
+) {
+    Card(
+        modifier = Modifier.fillMaxWidth(),
+        colors =
+            CardDefaults.cardColors(
+                containerColor = MaterialTheme.colorScheme.surface,
+            ),
+        elevation = CardDefaults.cardElevation(defaultElevation = 1.dp),
+    ) {
+        Row(
+            modifier = Modifier.padding(16.dp).fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.Top,
+        ) {
+            Column(modifier = Modifier.weight(1f)) {
+                Text(
+                    text = "\u201C${highlight.text}\u201D",
+                    style = MaterialTheme.typography.bodyMedium,
+                    fontStyle = FontStyle.Italic,
+                    color = MaterialTheme.colorScheme.onSurface,
+                )
+
+                val noteText = highlight.note
+                if (!noteText.isNullOrBlank()) {
+                    Spacer(Modifier.height(4.dp))
+                    Text(
+                        text = noteText,
+                        style = MaterialTheme.typography.bodySmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+
+                Spacer(Modifier.height(4.dp))
+                Row(
+                    horizontalArrangement = Arrangement.spacedBy(8.dp),
+                    verticalAlignment = Alignment.CenterVertically,
+                ) {
+                    Text(
+                        text = formatTimestamp(highlight.createdAt),
+                        style = MaterialTheme.typography.labelSmall,
+                        color = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                    Icon(
+                        imageVector = if (highlight.published) Icons.Default.Public else Icons.Default.Lock,
+                        contentDescription = if (highlight.published) "Published" else "Private",
+                        modifier = Modifier.size(14.dp),
+                        tint = MaterialTheme.colorScheme.onSurfaceVariant,
+                    )
+                }
+            }
+
+            IconButton(onClick = onDelete) {
+                Icon(
+                    Icons.Default.Delete,
+                    contentDescription = "Delete highlight",
+                    tint = MaterialTheme.colorScheme.error,
+                )
+            }
+        }
+    }
+}
+
+private fun formatTimestamp(epochSeconds: Long): String =
+    Instant
+        .ofEpochSecond(epochSeconds)
+        .atZone(ZoneId.systemDefault())
+        .format(DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"))

docs/plans/2026-03-24-feat-article-highlights-notes-plan.md

@@ -0,0 +1,410 @@
+---
+title: "feat: Article Highlights & Note-Taking"
+type: feat
+status: active
+date: 2026-03-24
+deepened: 2026-03-24
+origin: docs/brainstorms/2026-03-24-article-highlights-notes-brainstorm.md
+---
+
+# feat: Article Highlights & Note-Taking
+
+## Enhancement Summary
+
+**Deepened on:** 2026-03-24
+**Research agents used:** text-selection, richtext-rendering, floating-popup, nip84-highlights
+
+### Key Improvements
+1. **Text selection strategy resolved** — Use `LocalTextContextMenu` override (only official API exposing selected text), not clipboard polling
+2. **Inline rendering strategy resolved** — Pre-process markdown with special link URI (`highlight://`) as v1; fork-level `==highlight==` syntax as v2
+3. **Floating toolbar pattern confirmed** — `Popup` + custom `PopupPositionProvider`, matches existing `ChatPane.kt` pattern
+4. **NIP-84 gap found** — `HighlightEvent.create()` only takes `msg`+`signer`, needs tag assembly wrapper for full highlight creation
+
+### Resolved Questions
+- **`<mark>` support?** No — richtext library ignores `HtmlInline` nodes. Use pre-processing or fork changes.
+- **Clipboard polling reliability?** Moot — use `LocalTextContextMenu` instead (right-click UX, official API)
+- **NIP-09 deletion?** Yes — send kind 5 event with `["e", highlightEventId]` + `["k", "9802"]`
+
+## Overview
+
+Text selection-based highlight and annotation system for the Desktop article reader. Users select text in NIP-23 articles, a context menu option or floating toolbar appears, and they create highlights (with optional notes). Highlights render inline as colored markers. Supports private (local) and public (NIP-84) modes. Includes a "My Highlights" aggregation screen.
+
+## Problem Statement
+
+Desktop article reader has no way to mark up, annotate, or take notes on long-form content. Users reading NIP-23 articles can't highlight passages, add personal notes, or publish highlights to their Nostr social graph. This limits the reading experience compared to tools like Kindle, Medium, or Hypothesis.
+
+## Proposed Solution
+
+Three-phase implementation:
+1. **Storage + data model** — DesktopHighlightStore (Preferences-based) + highlight data classes
+2. **Selection UX + inline rendering** — Text selection interception via context menu, floating toolbar, yellow highlight markers in markdown
+3. **My Highlights screen + NIP-84 publishing** — Aggregation view, public/private toggle, relay broadcast
+
+## Technical Approach
+
+### Architecture
+
+```
+desktopApp/
+├── service/highlights/
+│   └── DesktopHighlightStore.kt    # Preferences-based storage (like DraftStore)
+├── ui/
+│   ├── ArticleReaderScreen.kt      # Modified: selection + inline highlights
+│   ├── highlights/
+│   │   ├── FloatingHighlightToolbar.kt  # Popup on text selection
+│   │   ├── HighlightAnnotationDialog.kt # Note entry dialog
+│   │   ├── HighlightPublishAction.kt    # NIP-84 tag assembly + publish
+│   │   └── MyHighlightsScreen.kt        # Aggregation screen
+│   └── deck/
+│       ├── DeckColumnType.kt       # Add MyHighlights
+│       ├── DeckColumnContainer.kt  # Route MyHighlights
+│       └── SinglePaneLayout.kt     # Add nav item
+
+commons/
+├── compose/markdown/
+│   └── RenderMarkdown.kt          # Modified: accept highlight ranges, render yellow bg
+├── model/highlights/
+│   └── HighlightData.kt           # Shared data class
+```
+
+### Implementation Phases
+
+#### Phase 1: Storage & Data Model
+
+**Goal:** DesktopHighlightStore + highlight data classes, no UI yet.
+
+**Files:**
+- `desktopApp/service/highlights/DesktopHighlightStore.kt` — follows DesktopDraftStore pattern (Jackson + Preferences)
+- `commons/model/highlights/HighlightData.kt` — shared data class
+
+**Data model:**
+```kotlin
+data class HighlightData(
+    val id: String,           // UUID
+    val text: String,         // selected/highlighted text
+    val note: String?,        // optional annotation
+    val articleAddressTag: String, // "30023:pubkey:d-tag"
+    val articleTitle: String?, // cached for My Highlights display
+    val createdAt: Long,      // epoch seconds
+    val published: Boolean,   // false = private, true = NIP-84 published
+    val eventId: String?,     // NIP-84 event ID if published
+)
+```
+
+**DesktopHighlightStore API:**
+```kotlin
+class DesktopHighlightStore(scope: CoroutineScope) {
+    private val mapper = jacksonObjectMapper()
+    val highlights: StateFlow<Map<String, List<HighlightData>>>  // keyed by articleAddressTag
+
+    suspend fun addHighlight(articleAddressTag: String, text: String, note: String?, articleTitle: String?)
+    suspend fun updateNote(highlightId: String, note: String)
+    suspend fun removeHighlight(highlightId: String)
+    suspend fun markPublished(highlightId: String, eventId: String)
+    fun getHighlightsForArticle(addressTag: String): List<HighlightData>
+    fun getAllHighlights(): Map<String, List<HighlightData>>
+}
+```
+
+**Tests:** Unit tests for store CRUD, serialization round-trip.
+
+**Success criteria:**
+- [ ] HighlightData serializes/deserializes via Jackson
+- [ ] Store persists across app restarts via Preferences
+- [ ] CRUD operations work correctly
+- [ ] StateFlow emits on changes
+
+### Research Insights — Phase 1
+
+**Storage pattern:** Follow `DesktopDraftStore.kt` exactly:
+- `jacksonObjectMapper()` for serialization (line 62)
+- Atomic writes with temp files + `Files.move()` (lines 237-254)
+- POSIX file permissions for security (lines 261-288)
+- Preferences key: `"highlights:${articleAddressTag}"` with JSON array value
+
+**Edge case — Preferences size limit:** `java.util.prefs.Preferences` has a per-value limit of 8192 bytes on some platforms. For articles with many highlights, the JSON array could exceed this. Mitigation: if value exceeds 6KB, spill to file-based storage (same pattern as DraftStore's file storage).
+
+---
+
+#### Phase 2: Selection UX + Inline Rendering
+
+**Goal:** Select text in article → create highlight → see yellow marker.
+
+##### Text Selection Strategy (REVISED)
+
+**Primary: `LocalTextContextMenu` override** — the only official Compose Desktop API that exposes `selectedText`:
+
+```kotlin
+@Composable
+fun HighlightableContent(
+    onHighlight: (String) -> Unit,
+    onAnnotate: (String) -> Unit,
+    content: @Composable () -> Unit,
+) {
+    val defaultMenu = LocalTextContextMenu.current
+
+    CompositionLocalProvider(
+        LocalTextContextMenu provides object : TextContextMenu {
+            @Composable
+            override fun Area(
+                textManager: TextContextMenu.TextManager,
+                state: ContextMenuState,
+                content: @Composable () -> Unit,
+            ) {
+                ContextMenuDataProvider({
+                    val selected = textManager.selectedText
+                    if (selected.text.isNotEmpty()) {
+                        listOf(
+                            ContextMenuItem("Highlight") { onHighlight(selected.text) },
+                            ContextMenuItem("Highlight with Note") { onAnnotate(selected.text) },
+                        )
+                    } else {
+                        emptyList()
+                    }
+                }) {
+                    defaultMenu.Area(textManager, state, content = content)
+                }
+            }
+        },
+        content = content,
+    )
+}
+```
+
+**UX:** Select text → right-click → "Highlight" / "Highlight with Note" in context menu. Natural desktop UX. No clipboard polling needed.
+
+**Secondary: Keyboard shortcut (Cmd+H)** — reads clipboard after user copies:
+
+```kotlin
+Modifier.onPreviewKeyEvent { event ->
+    if (event.isMetaPressed && event.key == Key.H && event.type == KeyEventType.KeyDown) {
+        val clipText = clipboard.getText()?.text
+        if (!clipText.isNullOrBlank()) onHighlight(clipText)
+        true
+    } else false
+}
+```
+
+##### Inline Rendering Strategy (REVISED)
+
+**Research finding:** richtext library ignores `HtmlInline` (`<mark>`) and has no `Highlight` format. Three options ranked:
+
+| Approach | Effort | Quality | Recommended |
+|----------|--------|---------|-------------|
+| Pre-process: wrap in special link `[text](highlight://)` | Low | Hacky but works | v1 |
+| Fork: add `==text==` DelimiterProcessor + `Format.Highlight` | Medium | Clean, semantic | v2 |
+| Overlay: position colored Box composables | High | Fragile | No |
+
+**v1 approach (ship fast):** Pre-process markdown before parsing:
+```kotlin
+fun applyHighlights(content: String, highlights: List<HighlightData>): String {
+    var result = content
+    // Sort by length descending to avoid nested replacement issues
+    highlights.sortedByDescending { it.text.length }.forEach { h ->
+        val idx = result.indexOf(h.text)
+        if (idx >= 0) {
+            // Wrap in bold + italic to visually distinguish
+            result = result.replaceFirst(h.text, "***${h.text}***")
+        }
+    }
+    return result
+}
+```
+
+**v2 approach (proper):** Add highlight support to Vitor's richtext fork:
+1. Add `AstHighlight` inline node type
+2. Add `HighlightDelimiterProcessor` for `==text==` syntax
+3. Add `Format.Highlight` with `SpanStyle(background = Color(0xFFFFEB3B))`
+4. Pre-process: wrap highlights with `==text==` before parsing
+
+##### Floating Toolbar (for future enhancement beyond context menu)
+
+**Pattern:** `Popup` + custom `PopupPositionProvider` (matches existing `ChatPane.kt:584`):
+
+```kotlin
+class MousePositionProvider(private val offset: IntOffset) : PopupPositionProvider {
+    override fun calculatePosition(
+        anchorBounds: IntRect, windowSize: IntSize,
+        layoutDirection: LayoutDirection, popupContentSize: IntSize,
+    ): IntOffset {
+        val x = (offset.x - popupContentSize.width / 2)
+            .coerceIn(0, windowSize.width - popupContentSize.width)
+        val y = (offset.y - popupContentSize.height - 8)
+            .coerceIn(0, windowSize.height - popupContentSize.height)
+        return IntOffset(x, y)
+    }
+}
+```
+
+Track mouse via `Modifier.pointerInput` + `awaitPointerEventScope` (pattern from `VideoControls.kt:89`). Dismiss on scroll via `LaunchedEffect(scrollState.isScrollInProgress)`.
+
+**Files:**
+- `desktopApp/ui/highlights/FloatingHighlightToolbar.kt` — Popup with Highlight/Annotate buttons
+- `desktopApp/ui/highlights/HighlightAnnotationDialog.kt` — AlertDialog for note text
+- `desktopApp/ui/ArticleReaderScreen.kt` — Add context menu override, highlight state, inline rendering
+- `commons/compose/markdown/RenderMarkdown.kt` — Add `highlights: List<HighlightData>` param
+
+**UX flow (revised):**
+1. User reads article, selects text by click-dragging
+2. Right-click → context menu shows "Highlight" / "Highlight with Note" (via `LocalTextContextMenu`)
+3. "Highlight" → saves immediately via DesktopHighlightStore, re-renders with bold/italic marker (v1) or yellow bg (v2)
+4. "Highlight with Note" → opens HighlightAnnotationDialog → saves with note
+5. Click existing highlight → popup with note / delete / publish toggle
+
+**Success criteria:**
+- [ ] Right-click context menu shows "Highlight" option when text is selected
+- [ ] Highlight saves and renders as visual marker in article
+- [ ] Annotation dialog captures and saves notes
+- [ ] Highlights persist across navigation (leave article and return)
+- [ ] Best-effort match: highlights survive minor article edits (see brainstorm)
+- [ ] Cmd+H keyboard shortcut works as alternative (select, copy, Cmd+H)
+
+---
+
+#### Phase 3: My Highlights Screen + NIP-84 Publishing
+
+**Goal:** Aggregation screen showing all highlights grouped by article. Public/private toggle per highlight.
+
+**Files:**
+- `desktopApp/ui/highlights/MyHighlightsScreen.kt`
+- `desktopApp/ui/highlights/HighlightPublishAction.kt` — tag assembly + publish
+- `desktopApp/ui/deck/DeckColumnType.kt` — Add `object MyHighlights`
+- `desktopApp/ui/deck/DeckColumnContainer.kt` — Route MyHighlights
+- `desktopApp/ui/deck/SinglePaneLayout.kt` — Add nav item
+- `desktopApp/ui/deck/AddColumnDialog.kt` — Add to column options
+- `desktopApp/ui/deck/ColumnHeader.kt` — Add icon
+
+##### NIP-84 Publishing (REVISED)
+
+**Gap found:** `HighlightEvent.create()` only takes `msg` + `signer` — doesn't accept source/context/comment tags. Need a wrapper:
+
+```kotlin
+object HighlightPublishAction {
+    suspend fun publish(
+        highlightText: String,
+        articleEvent: LongTextNoteEvent,
+        note: String?,
+        signer: NostrSigner,
+    ): HighlightEvent {
+        val tags = TagArrayBuilder().apply {
+            // Article reference (addressable event)
+            add(ATag.assemble(30023, articleEvent.pubKey, articleEvent.dTag()))
+            // Article author attribution
+            add(PTag.assemble(articleEvent.pubKey, role = "author"))
+            // Optional annotation
+            note?.let { add(CommentTag.assemble(it)) }
+            // Surrounding paragraph as context
+            extractContext(articleEvent.content, highlightText)?.let {
+                add(ContextTag.assemble(it))
+            }
+            // Alt text for non-NIP-84 clients
+            add(AltTag.assemble("Highlight: $highlightText"))
+        }.build()
+
+        return HighlightEvent.create(
+            msg = highlightText,
+            tags = tags,
+            signer = signer,
+        )
+    }
+
+    /** Extract the paragraph containing the highlighted text */
+    fun extractContext(content: String, highlightText: String): String? {
+        val paragraphs = content.split("\n\n")
+        return paragraphs.find { it.contains(highlightText) }
+    }
+}
+```
+
+##### NIP-09 Deletion for Published Highlights
+
+```kotlin
+suspend fun deleteHighlight(eventId: String, signer: NostrSigner): DeletionEvent {
+    return DeletionEvent.create(
+        deleteEvents = listOf(eventId),
+        deleteKinds = listOf(9802),
+        reason = "User deleted highlight",
+        signer = signer,
+    )
+}
+```
+
+**My Highlights screen layout:**
+```
+┌─────────────────────────────────┐
+│ My Highlights                   │
+├─────────────────────────────────┤
+│ ▼ "Article Title One"           │
+│   "highlighted text..."    🔒   │
+│   Note: my annotation      ╳   │
+│   Mar 24, 2026                  │
+│                                 │
+│   "another highlight..."   🌐   │
+│   Mar 24, 2026                  │
+│                                 │
+│ ▼ "Article Title Two"           │
+│   "highlighted passage..." 🔒   │
+│   Note: thoughts here      ╳   │
+└─────────────────────────────────┘
+🔒 = private  🌐 = published
+Click article title → navigates to article
+Click 🔒 → publish to Nostr (NIP-84)
+Click ╳ → delete (+ NIP-09 if published)
+```
+
+**Success criteria:**
+- [ ] My Highlights accessible from sidebar nav
+- [ ] Highlights grouped by article with collapsible sections
+- [ ] Click article title navigates to article (onNavigateToArticle)
+- [ ] Public/private toggle publishes NIP-84 event to relays
+- [ ] Delete removes from local store + sends NIP-09 deletion for published
+- [ ] Empty state when no highlights exist
+
+## Acceptance Criteria
+
+- [ ] Right-click selected text in article → "Highlight" in context menu
+- [ ] Click "Highlight" → text marked visually, saved locally
+- [ ] Click "Highlight with Note" → note dialog, then saved with annotation
+- [ ] Cmd+H keyboard shortcut creates highlight from clipboard
+- [ ] Highlights persist across app restarts
+- [ ] Highlights survive article content updates (best-effort string match)
+- [ ] "My Highlights" screen shows all highlights grouped by article
+- [ ] Can toggle highlight public/private (publishes NIP-84 event)
+- [ ] Can delete highlights (+ NIP-09 for published)
+- [ ] Zoom (Cmd+/Cmd-) doesn't break highlight rendering
+- [ ] Works in both single-pane and deck layout modes
+
+## Dependencies & Risks
+
+| Risk | Impact | Mitigation | Status |
+|------|--------|------------|--------|
+| `SelectionContainer` doesn't expose selection state | High | **Resolved:** Use `LocalTextContextMenu` override — official API, accesses `selectedText` directly | Mitigated |
+| richtext library doesn't support `<mark>` or highlight formatting | Medium | **Resolved:** v1 uses bold/italic pre-processing; v2 adds `Format.Highlight` to fork | Mitigated |
+| `LocalTextContextMenu.TextManager.selectedText` doesn't work across multiple `Text()` children | Medium | Test during Phase 2; fallback to clipboard-based Cmd+H shortcut | Open |
+| `HighlightEvent.create()` doesn't accept custom tags | Low | **Resolved:** Create `HighlightPublishAction` wrapper with `TagArrayBuilder` | Mitigated |
+| Preferences 8KB per-value limit | Low | Monitor; spill to file storage if needed | Open |
+
+## Sources & References
+
+### Origin
+
+- **Brainstorm:** [docs/brainstorms/2026-03-24-article-highlights-notes-brainstorm.md](docs/brainstorms/2026-03-24-article-highlights-notes-brainstorm.md)
+  - Key decisions: private+public scope, select+popup UX, Preferences storage, own highlights only, best-effort persistence, My Highlights screen
+
+### Internal References
+
+- HighlightEvent protocol: `quartz/nip84Highlights/HighlightEvent.kt:137-141`
+- DraftStore pattern: `desktopApp/service/drafts/DesktopDraftStore.kt`
+- Event publishing: `desktopApp/ui/ArticleEditorScreen.kt:161-187`
+- SelectionContainer: `desktopApp/ui/ArticleEditorScreen.kt:304`
+- Context menu override: `LocalTextContextMenu` (Compose Desktop API)
+- Popup pattern: `desktopApp/ui/chats/ChatPane.kt:584`
+- Mouse tracking: `desktopApp/ui/media/VideoControls.kt:89`
+- Android highlight rendering: `amethyst/ui/note/types/Highlight.kt:179-198`
+
+### External References
+
+- [Compose Desktop context menus](https://kotlinlang.org/docs/multiplatform/compose-desktop-context-menus.html)
+- [NIP-84 spec (Highlights)](https://github.com/nostr-protocol/nips/blob/master/84.md)
+- [NIP-09 spec (Event Deletion)](https://github.com/nostr-protocol/nips/blob/master/09.md)
+- [commonmark-java DelimiterProcessor](https://github.com/commonmark/commonmark-java)