agent: Render diffs for the edit file tool (#29234)

This PR implements the `ToolCard` for the edit file tool, which allow us
to display an editor with a diff in the thread view with the changes
performed by the model.

- [x] Fix buffer sometimes displaying empty
- [x] Stop buffer from scrolling together with the thread
- [x] Fix multibuffer header sometimes appearing
- [x] Fix buffer height issue
- [x] Implement "full height" expand button
- [x] Add "Jump To File" functionality
- [x] Polish and refine styles

Release Notes:

- agent: Added diff preview cards in the thread view for edits performed
by the agent.

---------

Co-authored-by: João Marcos <marcospb19@hotmail.com>
Co-authored-by: Richard Feldman <oss@rtfeldman.com>
Co-authored-by: Agus Zubiaga <hi@aguz.me>
Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/assistant_tools/src/batch_tool.rs

@@ -2,7 +2,7 @@ use crate::schema::json_schema_for;
 use anyhow::{Result, anyhow};
 use assistant_tool::{ActionLog, Tool, ToolResult, ToolWorkingSet};
 use futures::future::join_all;
-use gpui::{App, AppContext, Entity, Task};
+use gpui::{AnyWindowHandle, App, AppContext, Entity, Task};
 use language_model::{LanguageModelRequestMessage, LanguageModelToolSchemaFormat};
 use project::Project;
 use schemars::JsonSchema;
@@ -218,6 +218,7 @@ impl Tool for BatchTool {
         messages: &[LanguageModelRequestMessage],
         project: Entity<Project>,
         action_log: Entity<ActionLog>,
+        window: Option<AnyWindowHandle>,
         cx: &mut App,
     ) -> ToolResult {
         let input = match serde_json::from_value::<BatchToolInput>(input) {
@@ -258,7 +259,9 @@ impl Tool for BatchTool {
                     let action_log = action_log.clone();
                     let messages = messages.clone();
                     let tool_result = cx
-                        .update(|cx| tool.run(invocation.input, &messages, project, action_log, cx))
+                        .update(|cx| {
+                            tool.run(invocation.input, &messages, project, action_log, window, cx)
+                        })
                         .map_err(|err| anyhow!("Failed to start tool '{}': {}", tool_name, err))?;
 
                     tasks.push(tool_result.output);