Extract an agent_ui crate from agent (#33284)

This PR moves the UI-dependent logic in the `agent` crate into its own
crate, `agent_ui`. The remaining `agent` crate no longer depends on
`editor`, `picker`, `ui`, `workspace`, etc.

This has compile time benefits, but the main motivation is to isolate
our core agentic logic, so that we can make agents more
pluggable/configurable.

Release Notes:

- N/A

crates/zed/Cargo.toml

@@ -21,6 +21,7 @@ path = "src/main.rs"
 [dependencies]
 activity_indicator.workspace = true
 agent.workspace = true
+agent_ui.workspace = true
 agent_settings.workspace = true
 anyhow.workspace = true
 askpass.workspace = true

crates/zed/src/main.rs

@@ -531,7 +531,7 @@ pub fn main() {
             cx,
         );
         let prompt_builder = PromptBuilder::load(app_state.fs.clone(), stdout_is_a_pty(), cx);
-        agent::init(
+        agent_ui::init(
             app_state.fs.clone(),
             app_state.client.clone(),
             prompt_builder.clone(),

crates/zed/src/zed.rs

@@ -9,7 +9,7 @@ mod quick_action_bar;
 #[cfg(target_os = "windows")]
 pub(crate) mod windows_only_instance;
 
-use agent::AgentDiffToolbar;
+use agent_ui::AgentDiffToolbar;
 use anyhow::Context as _;
 pub use app_menus::*;
 use assets::Assets;
@@ -515,7 +515,7 @@ fn initialize_panels(
         let is_assistant2_enabled = !cfg!(test);
         let agent_panel = if is_assistant2_enabled {
             let agent_panel =
-                agent::AgentPanel::load(workspace_handle.clone(), prompt_builder, cx.clone())
+                agent_ui::AgentPanel::load(workspace_handle.clone(), prompt_builder, cx.clone())
                     .await?;
 
             Some(agent_panel)
@@ -536,13 +536,13 @@ fn initialize_panels(
             // Once we ship `assistant2` we can push this back down into `agent::agent_panel::init`.
             if is_assistant2_enabled {
                 <dyn AgentPanelDelegate>::set_global(
-                    Arc::new(agent::ConcreteAssistantPanelDelegate),
+                    Arc::new(agent_ui::ConcreteAssistantPanelDelegate),
                     cx,
                 );
 
                 workspace
-                    .register_action(agent::AgentPanel::toggle_focus)
-                    .register_action(agent::InlineAssistant::inline_assist);
+                    .register_action(agent_ui::AgentPanel::toggle_focus)
+                    .register_action(agent_ui::InlineAssistant::inline_assist);
             }
         })?;
 
@@ -4320,7 +4320,7 @@ mod tests {
             web_search::init(cx);
             web_search_providers::init(app_state.client.clone(), cx);
             let prompt_builder = PromptBuilder::load(app_state.fs.clone(), false, cx);
-            agent::init(
+            agent_ui::init(
                 app_state.fs.clone(),
                 app_state.client.clone(),
                 prompt_builder.clone(),

crates/zed/src/zed/component_preview.rs

@@ -5,20 +5,14 @@
 mod persistence;
 mod preview_support;
 
-use std::ops::Range;
-use std::sync::Arc;
-
-use std::iter::Iterator;
-
-use agent::{ActiveThread, TextThreadStore, ThreadStore};
+use agent::{TextThreadStore, ThreadStore};
+use agent_ui::ActiveThread;
 use client::UserStore;
+use collections::HashMap;
 use component::{ComponentId, ComponentMetadata, ComponentStatus, components};
 use gpui::{
     App, Entity, EventEmitter, FocusHandle, Focusable, Task, WeakEntity, Window, list, prelude::*,
 };
-
-use collections::HashMap;
-
 use gpui::{ListState, ScrollHandle, ScrollStrategy, UniformListScrollHandle};
 use languages::LanguageRegistry;
 use notifications::status_toast::{StatusToast, ToastIcon};
@@ -27,11 +21,14 @@ use preview_support::active_thread::{
     load_preview_text_thread_store, load_preview_thread_store, static_active_thread,
 };
 use project::Project;
+use std::{iter::Iterator, ops::Range, sync::Arc};
 use ui::{ButtonLike, Divider, HighlightedLabel, ListItem, ListSubHeader, Tooltip, prelude::*};
 use ui_input::SingleLineInput;
 use util::ResultExt as _;
-use workspace::{AppState, ItemId, SerializableItem, delete_unloaded_items};
-use workspace::{Item, Workspace, WorkspaceId, item::ItemEvent};
+use workspace::{
+    AppState, Item, ItemId, SerializableItem, Workspace, WorkspaceId, delete_unloaded_items,
+    item::ItemEvent,
+};
 
 pub fn init(app_state: Arc<AppState>, cx: &mut App) {
     workspace::register_serializable_item::<ComponentPreview>(cx);
@@ -642,7 +639,7 @@ impl ComponentPreview {
         // Check if the component's scope is Agent
         if scope == ComponentScope::Agent {
             if let Some(active_thread) = self.active_thread.clone() {
-                if let Some(element) = agent::get_agent_preview(
+                if let Some(element) = agent_ui::get_agent_preview(
                     &component.id(),
                     self.workspace.clone(),
                     active_thread,
@@ -1140,7 +1137,7 @@ impl ComponentPreviewPage {
     fn render_preview(&self, window: &mut Window, cx: &mut App) -> impl IntoElement {
         // Try to get agent preview first if we have an active thread
         let maybe_agent_preview = if let Some(active_thread) = self.active_thread.as_ref() {
-            agent::get_agent_preview(
+            agent_ui::get_agent_preview(
                 &self.component.id(),
                 self.workspace.clone(),
                 active_thread.clone(),

crates/zed/src/zed/component_preview/preview_support/active_thread.rs

@@ -1,4 +1,5 @@
-use agent::{ActiveThread, ContextStore, MessageSegment, TextThreadStore, ThreadStore};
+use agent::{ContextStore, MessageSegment, TextThreadStore, ThreadStore};
+use agent_ui::ActiveThread;
 use anyhow::{Result, anyhow};
 use assistant_tool::ToolWorkingSet;
 use gpui::{AppContext, AsyncApp, Entity, Task, WeakEntity};