feat(chat): add copy, share, and edit action buttons above input bar

Add ChatActionBar component with three icon buttons above the chat
input:
- Copy: copies last assistant response to clipboard
- Share: copies full conversation text to clipboard
- Edit: removes last user message and places it back in input

Buttons are disabled when no relevant messages exist.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

assets/main.css

@@ -1884,6 +1884,44 @@ h6 {
     color: var(--accent);
 }
 
+/* -- Chat Action Bar -- */
+.chat-action-bar {
+    display: flex;
+    align-items: center;
+    gap: 4px;
+    padding: 4px 24px 0;
+    background-color: var(--bg-sidebar);
+}
+
+.chat-action-btn {
+    display: inline-flex;
+    align-items: center;
+    gap: 5px;
+    padding: 4px 10px;
+    background: none;
+    border: 1px solid transparent;
+    border-radius: 6px;
+    color: var(--text-secondary);
+    font-size: 12px;
+    cursor: pointer;
+    transition: all 0.15s ease;
+}
+
+.chat-action-btn:hover:not(:disabled) {
+    color: var(--text-primary);
+    background-color: var(--bg-card);
+    border-color: var(--border-secondary);
+}
+
+.chat-action-btn:disabled {
+    opacity: 0.35;
+    cursor: not-allowed;
+}
+
+.chat-action-label {
+    font-family: 'Inter', sans-serif;
+}
+
 /* -- Chat Input Bar -- */
 .chat-input-bar {
     display: flex;

src/components/chat_action_bar.rs

@@ -0,0 +1,65 @@
+use dioxus::prelude::*;
+use dioxus_free_icons::icons::fa_solid_icons::{FaCopy, FaPenToSquare, FaShareNodes};
+
+/// Action bar displayed above the chat input with copy, share, and edit buttons.
+///
+/// Only visible when there is at least one message in the conversation.
+///
+/// # Arguments
+///
+/// * `on_copy` - Copies the last assistant response to the clipboard
+/// * `on_share` - Copies the full conversation as text to the clipboard
+/// * `on_edit` - Places the last user message back in the input for editing
+/// * `has_messages` - Whether any messages exist (hides the bar when empty)
+/// * `has_assistant_message` - Whether an assistant message exists (disables copy if not)
+/// * `has_user_message` - Whether a user message exists (disables edit if not)
+#[component]
+pub fn ChatActionBar(
+    on_copy: EventHandler<()>,
+    on_share: EventHandler<()>,
+    on_edit: EventHandler<()>,
+    has_messages: bool,
+    has_assistant_message: bool,
+    has_user_message: bool,
+) -> Element {
+    if !has_messages {
+        return rsx! {};
+    }
+
+    rsx! {
+        div { class: "chat-action-bar",
+            button {
+                class: "chat-action-btn",
+                disabled: !has_assistant_message,
+                title: "Copy last response",
+                onclick: move |_| on_copy.call(()),
+                dioxus_free_icons::Icon {
+                    icon: FaCopy,
+                    width: 14, height: 14,
+                }
+                span { class: "chat-action-label", "Copy" }
+            }
+            button {
+                class: "chat-action-btn",
+                title: "Copy conversation",
+                onclick: move |_| on_share.call(()),
+                dioxus_free_icons::Icon {
+                    icon: FaShareNodes,
+                    width: 14, height: 14,
+                }
+                span { class: "chat-action-label", "Share" }
+            }
+            button {
+                class: "chat-action-btn",
+                disabled: !has_user_message,
+                title: "Edit last message",
+                onclick: move |_| on_edit.call(()),
+                dioxus_free_icons::Icon {
+                    icon: FaPenToSquare,
+                    width: 14, height: 14,
+                }
+                span { class: "chat-action-label", "Edit" }
+            }
+        }
+    }
+}

src/components/mod.rs

@@ -1,6 +1,7 @@
 mod app_shell;
 mod article_detail;
 mod card;
+mod chat_action_bar;
 mod chat_bubble;
 mod chat_input_bar;
 mod chat_message_list;
@@ -20,6 +21,7 @@ mod tool_card;
 pub use app_shell::*;
 pub use article_detail::*;
 pub use card::*;
+pub use chat_action_bar::*;
 pub use chat_bubble::*;
 pub use chat_input_bar::*;
 pub use chat_message_list::*;

src/pages/chat.rs

@@ -1,4 +1,6 @@
-use crate::components::{ChatInputBar, ChatMessageList, ChatModelSelector, ChatSidebar};
+use crate::components::{
+    ChatActionBar, ChatInputBar, ChatMessageList, ChatModelSelector, ChatSidebar,
+};
 use crate::infrastructure::chat::{
     chat_complete, create_chat_session, delete_chat_session, list_chat_messages,
     list_chat_sessions, rename_chat_session, save_chat_message,
@@ -16,7 +18,7 @@ pub fn ChatPage() -> Element {
     // ---- Signals ----
     let mut active_session_id: Signal<Option<String>> = use_signal(|| None);
     let mut messages: Signal<Vec<ChatMessage>> = use_signal(Vec::new);
-    let input_text: Signal<String> = use_signal(String::new);
+    let mut input_text: Signal<String> = use_signal(String::new);
     let mut is_streaming: Signal<bool> = use_signal(|| false);
     let mut streaming_content: Signal<String> = use_signal(String::new);
     let mut selected_model: Signal<String> = use_signal(String::new);
@@ -202,6 +204,77 @@ pub fn ChatPage() -> Element {
         });
     };
 
+    // ---- Action bar state ----
+    let has_messages = !messages.read().is_empty();
+    let has_assistant_message = messages
+        .read()
+        .iter()
+        .any(|m| m.role == ChatRole::Assistant);
+    let has_user_message = messages.read().iter().any(|m| m.role == ChatRole::User);
+
+    // Copy last assistant response to clipboard
+    let on_copy = move |_: ()| {
+        #[cfg(feature = "web")]
+        {
+            let last_assistant = messages
+                .read()
+                .iter()
+                .rev()
+                .find(|m| m.role == ChatRole::Assistant)
+                .map(|m| m.content.clone());
+            if let Some(text) = last_assistant {
+                if let Some(window) = web_sys::window() {
+                    let clipboard = window.navigator().clipboard();
+                    let _ = clipboard.write_text(&text);
+                }
+            }
+        }
+    };
+
+    // Copy full conversation as text to clipboard
+    let on_share = move |_: ()| {
+        #[cfg(feature = "web")]
+        {
+            let text: String = messages
+                .read()
+                .iter()
+                .filter(|m| m.role != ChatRole::System)
+                .map(|m| {
+                    let label = match m.role {
+                        ChatRole::User => "You",
+                        ChatRole::Assistant => "Assistant",
+                        ChatRole::System => "System",
+                    };
+                    format!("{label}:\n{}\n", m.content)
+                })
+                .collect::<Vec<_>>()
+                .join("\n");
+            if let Some(window) = web_sys::window() {
+                let clipboard = window.navigator().clipboard();
+                let _ = clipboard.write_text(&text);
+            }
+        }
+    };
+
+    // Edit last user message: remove it and place text back in input
+    let on_edit = move |_: ()| {
+        let last_user = messages
+            .read()
+            .iter()
+            .rev()
+            .find(|m| m.role == ChatRole::User)
+            .map(|m| m.content.clone());
+        if let Some(text) = last_user {
+            // Remove the last user message (and any assistant reply after it)
+            let mut msgs = messages.read().clone();
+            if let Some(pos) = msgs.iter().rposition(|m| m.role == ChatRole::User) {
+                msgs.truncate(pos);
+                messages.set(msgs);
+            }
+            input_text.set(text);
+        }
+    };
+
     // Scroll to bottom when messages or streaming content changes
     let msg_count = messages.read().len();
     let stream_len = streaming_content.read().len();
@@ -244,6 +317,14 @@ pub fn ChatPage() -> Element {
                     streaming_content: streaming_content.read().clone(),
                     is_streaming: *is_streaming.read(),
                 }
+                ChatActionBar {
+                    on_copy: on_copy,
+                    on_share: on_share,
+                    on_edit: on_edit,
+                    has_messages: has_messages,
+                    has_assistant_message: has_assistant_message,
+                    has_user_message: has_user_message,
+                }
                 ChatInputBar {
                     input_text: input_text,
                     on_send: on_send,