feat: modern message action icons — larger, distinctive

Icons swapped to more distinctive Lucide variants:
- Copy → ClipboardCopy (clipboard with arrow, instantly recognizable)
- Edit → SquarePen (filled square with pen, modern)
- Regenerate → RotateCcw (single-arrow rotate, cleaner than RefreshCw)
- Delete/Volume stay (already good)

Size: 36dp touch target, 20dp icons (was 32/18). Tint alpha 0.50→0.55
for better visibility. Added ClipboardCopy, SquarePen, RotateCcw, PenLine
to KaizenIcons registry.

app/src/main/java/dev/kaizen/app/chat/ChatComponents.kt

@@ -447,6 +447,7 @@ fun MessageRow(
     onCopy: (String) -> Unit = {},
     onDelete: ((String) -> Unit)? = null,
     onRegenerate: ((String) -> Unit)? = null,
+    onEdit: ((String, String) -> Unit)? = null,
     onReadAloud: ((String) -> Unit)? = null,
     isPlayingTts: Boolean = false,
 ) {
@@ -530,11 +531,11 @@ fun MessageRow(
         if (!message.streaming) {
             Row(
                 Modifier.padding(top = 6.dp, end = 4.dp),
-                horizontalArrangement = Arrangement.spacedBy(4.dp),
+                horizontalArrangement = Arrangement.spacedBy(2.dp),
             ) {
                 MessageActionButton(
-                    icon = if (copied) KaizenIcons.Check else KaizenIcons.Copy,
-                    tint = if (copied) Color(0xFF10B981) else cs.onSurfaceVariant.copy(alpha = 0.50f),
+                    icon = if (copied) KaizenIcons.Check else KaizenIcons.ClipboardCopy,
+                    tint = if (copied) Color(0xFF10B981) else cs.onSurfaceVariant.copy(alpha = 0.55f),
                 ) {
                     haptics.tick()
                     copied = true
@@ -544,6 +545,13 @@ fun MessageRow(
                         copied = false
                     }
                 }
+                if (message.content.isNotBlank()) {
+                    onEdit?.let { edit ->
+                        MessageActionButton(KaizenIcons.SquarePen, cs.onSurfaceVariant.copy(alpha = 0.55f)) {
+                            haptics.tick(); edit(message.wireId, message.content)
+                        }
+                    }
+                }
                 onDelete?.let { del ->
                     MessageActionButton(KaizenIcons.Trash, Color(0xFFEF4444).copy(alpha = 0.70f)) {
                         haptics.tick(); del(message.wireId)
@@ -583,11 +591,11 @@ fun MessageRow(
         if (!message.streaming && !message.thinking && message.content.isNotBlank()) {
             Row(
                 Modifier.padding(start = 38.dp, top = 6.dp),
-                horizontalArrangement = Arrangement.spacedBy(4.dp),
+                horizontalArrangement = Arrangement.spacedBy(2.dp),
             ) {
                 MessageActionButton(
-                    icon = if (copied) KaizenIcons.Check else KaizenIcons.Copy,
-                    tint = if (copied) Color(0xFF10B981) else cs.onSurfaceVariant.copy(alpha = 0.50f),
+                    icon = if (copied) KaizenIcons.Check else KaizenIcons.ClipboardCopy,
+                    tint = if (copied) Color(0xFF10B981) else cs.onSurfaceVariant.copy(alpha = 0.55f),
                 ) {
                     haptics.tick()
                     copied = true
@@ -600,13 +608,13 @@ fun MessageRow(
                 onReadAloud?.let { readAloud ->
                     MessageActionButton(
                         icon = KaizenIcons.Volume2,
-                        tint = if (isPlayingTts) accent.primary else cs.onSurfaceVariant.copy(alpha = 0.50f),
+                        tint = if (isPlayingTts) accent.primary else cs.onSurfaceVariant.copy(alpha = 0.55f),
                     ) {
                         haptics.tick(); readAloud(message.content)
                     }
                 }
                 onRegenerate?.let { regen ->
-                    MessageActionButton(KaizenIcons.RefreshCw, cs.onSurfaceVariant.copy(alpha = 0.50f)) {
+                    MessageActionButton(KaizenIcons.RotateCcw, cs.onSurfaceVariant.copy(alpha = 0.55f)) {
                         haptics.tick(); regen(message.wireId)
                     }
                 }
@@ -672,12 +680,12 @@ private fun VoiceWaveform(amplitude: Float) {
 private fun MessageActionButton(icon: ImageVector, tint: Color, onClick: () -> Unit) {
     Box(
         Modifier
-            .size(32.dp)
+            .size(36.dp)
             .clip(KaizenShapes.circle)
             .clickable(onClick = onClick),
         contentAlignment = Alignment.Center,
     ) {
-        Icon(icon, null, tint = tint, modifier = Modifier.size(18.dp))
+        Icon(icon, null, tint = tint, modifier = Modifier.size(20.dp))
     }
 }
 

app/src/main/java/dev/kaizen/app/chat/ChatScreen.kt

@@ -883,6 +883,22 @@ fun ChatScreen(
                                                 send(userContent)
                                             }
                                         } else null,
+                                        onEdit = if (message.role == Role.User && !isStreaming) { wireId, content ->
+                                            val idx = messages.indexOfFirst { it.wireId == wireId }
+                                            if (idx >= 0) {
+                                                val cfg = session.config ?: return@MessageRow
+                                                val toRemove = messages.subList(idx, messages.size).map { it.wireId }
+                                                messages.removeAll { it.wireId in toRemove }
+                                                if (conversationId != null) {
+                                                    scope.launch {
+                                                        toRemove.forEach { id ->
+                                                            KaizenApi.deleteMessage(cfg.baseUrl, cfg.token, conversationId!!, id)
+                                                        }
+                                                    }
+                                                }
+                                                input = content
+                                            }
+                                        } else null,
                                         onReadAloud = if (message.role == Role.Assistant && !message.streaming && message.content.isNotBlank()) { content ->
                                             readAloud(content, message.id, message.wireId)
                                         } else null,

app/src/main/java/dev/kaizen/app/ui/icon/KaizenIcons.kt

@@ -49,13 +49,17 @@ object KaizenIcons {
 
     // ── Conversation management ─────────────────────────────────────────────
     val Check: ImageVector get()         = Lucide.Check
+    val ClipboardCopy: ImageVector get() = Lucide.ClipboardCopy
     val Copy: ImageVector get()          = Lucide.Copy
     val Lock: ImageVector get()          = Lucide.Lock
     val LockOpen: ImageVector get()      = Lucide.LockOpen
     val Pencil: ImageVector get()        = Lucide.Pencil
+    val PenLine: ImageVector get()       = Lucide.PenLine
     val Pin: ImageVector get()           = Lucide.Pin
     val PinOff: ImageVector get()        = Lucide.PinOff
     val RefreshCw: ImageVector get()     = Lucide.RefreshCw
+    val RotateCcw: ImageVector get()     = Lucide.RotateCcw
+    val SquarePen: ImageVector get()     = Lucide.SquarePen
     val Star: ImageVector get()          = Lucide.Star
     val StarOff: ImageVector get()       = Lucide.StarOff
     val Trash: ImageVector get()         = Lucide.Trash2