Pass up intent with completion requests (#31710)

This PR adds a new `intent` field to completion requests to assist in
categorizing them correctly.

Release Notes:

- N/A

---------

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

crates/agent/src/message_editor.rs

@@ -42,6 +42,7 @@ use theme::ThemeSettings;
 use ui::{Disclosure, KeyBinding, PopoverMenuHandle, Tooltip, prelude::*};
 use util::{ResultExt as _, maybe};
 use workspace::{CollaboratorId, Workspace};
+use zed_llm_client::CompletionIntent;
 
 use crate::context_picker::{ContextPicker, ContextPickerCompletionProvider, crease_for_mention};
 use crate::context_store::ContextStore;
@@ -375,7 +376,12 @@ impl MessageEditor {
             thread
                 .update(cx, |thread, cx| {
                     thread.advance_prompt_id();
-                    thread.send_to_model(model, Some(window_handle), cx);
+                    thread.send_to_model(
+                        model,
+                        CompletionIntent::UserPrompt,
+                        Some(window_handle),
+                        cx,
+                    );
                 })
                 .log_err();
         })
@@ -1280,6 +1286,7 @@ impl MessageEditor {
                     let request = language_model::LanguageModelRequest {
                         thread_id: None,
                         prompt_id: None,
+                        intent: None,
                         mode: None,
                         messages: vec![request_message],
                         tools: vec![],