agent: Make read_file and edit_file tool call titles more specific (#37639)

For read_file and edit_file, show the worktree-relative path if there's
only one visible worktree, and the "full path" otherwise. Also restores
the display of line numbers for read_file calls.

Release Notes:

- N/A

crates/agent2/src/tools/copy_path_tool.rs

@@ -58,7 +58,11 @@ impl AgentTool for CopyPathTool {
         ToolKind::Move
     }
 
-    fn initial_title(&self, input: Result<Self::Input, serde_json::Value>) -> ui::SharedString {
+    fn initial_title(
+        &self,
+        input: Result<Self::Input, serde_json::Value>,
+        _cx: &mut App,
+    ) -> ui::SharedString {
         if let Ok(input) = input {
             let src = MarkdownInlineCode(&input.source_path);
             let dest = MarkdownInlineCode(&input.destination_path);