Port terminal tool to agent2 (#35918)

Release Notes:

- N/A

---------

Co-authored-by: Ben Brandt <benjamin.j.brandt@gmail.com>

crates/acp_thread/src/terminal.rs

@@ -0,0 +1,87 @@
+use gpui::{App, AppContext, Context, Entity};
+use language::LanguageRegistry;
+use markdown::Markdown;
+use std::{path::PathBuf, process::ExitStatus, sync::Arc, time::Instant};
+
+pub struct Terminal {
+    command: Entity<Markdown>,
+    working_dir: Option<PathBuf>,
+    terminal: Entity<terminal::Terminal>,
+    started_at: Instant,
+    output: Option<TerminalOutput>,
+}
+
+pub struct TerminalOutput {
+    pub ended_at: Instant,
+    pub exit_status: Option<ExitStatus>,
+    pub was_content_truncated: bool,
+    pub original_content_len: usize,
+    pub content_line_count: usize,
+    pub finished_with_empty_output: bool,
+}
+
+impl Terminal {
+    pub fn new(
+        command: String,
+        working_dir: Option<PathBuf>,
+        terminal: Entity<terminal::Terminal>,
+        language_registry: Arc<LanguageRegistry>,
+        cx: &mut Context<Self>,
+    ) -> Self {
+        Self {
+            command: cx
+                .new(|cx| Markdown::new(command.into(), Some(language_registry.clone()), None, cx)),
+            working_dir,
+            terminal,
+            started_at: Instant::now(),
+            output: None,
+        }
+    }
+
+    pub fn finish(
+        &mut self,
+        exit_status: Option<ExitStatus>,
+        original_content_len: usize,
+        truncated_content_len: usize,
+        content_line_count: usize,
+        finished_with_empty_output: bool,
+        cx: &mut Context<Self>,
+    ) {
+        self.output = Some(TerminalOutput {
+            ended_at: Instant::now(),
+            exit_status,
+            was_content_truncated: truncated_content_len < original_content_len,
+            original_content_len,
+            content_line_count,
+            finished_with_empty_output,
+        });
+        cx.notify();
+    }
+
+    pub fn command(&self) -> &Entity<Markdown> {
+        &self.command
+    }
+
+    pub fn working_dir(&self) -> &Option<PathBuf> {
+        &self.working_dir
+    }
+
+    pub fn started_at(&self) -> Instant {
+        self.started_at
+    }
+
+    pub fn output(&self) -> Option<&TerminalOutput> {
+        self.output.as_ref()
+    }
+
+    pub fn inner(&self) -> &Entity<terminal::Terminal> {
+        &self.terminal
+    }
+
+    pub fn to_markdown(&self, cx: &App) -> String {
+        format!(
+            "Terminal:\n```\n{}\n```\n",
+            self.terminal.read(cx).get_content()
+        )
+    }
+}