Remove list_worktrees and use relative paths instead (#26546)

Release Notes:

- N/A

crates/prompt_store/src/prompts.rs

@@ -11,6 +11,11 @@ use std::{ops::Range, path::PathBuf, sync::Arc, time::Duration};
 use text::LineEnding;
 use util::ResultExt;
 
+#[derive(Serialize)]
+pub struct AssistantSystemPromptContext {
+    pub worktree_root_names: Vec<String>,
+}
+
 #[derive(Serialize)]
 pub struct ContentPromptDiagnosticContext {
     pub line_number: usize,
@@ -216,6 +221,18 @@ impl PromptBuilder {
         Ok(())
     }
 
+    pub fn generate_assistant_system_prompt(
+        &self,
+        worktree_root_names: Vec<String>,
+    ) -> Result<String, RenderError> {
+        let prompt = AssistantSystemPromptContext {
+            worktree_root_names,
+        };
+        self.handlebars
+            .lock()
+            .render("assistant_system_prompt", &prompt)
+    }
+
     pub fn generate_inline_transformation_prompt(
         &self,
         user_prompt: String,