edit prediction: Request trigger (#43588)

Adds a `trigger` field to the zeta1/zeta2 prediction requests so that we
can distinguish between editor, diagnostic, and zeta-cli requests.

Release Notes:

- N/A

crates/cloud_llm_client/src/cloud_llm_client.rs

@@ -169,6 +169,17 @@ pub struct PredictEditsBody {
     /// Info about the git repository state, only present when can_collect_data is true.
     #[serde(skip_serializing_if = "Option::is_none", default)]
     pub git_info: Option<PredictEditsGitInfo>,
+    /// The trigger for this request.
+    #[serde(default)]
+    pub trigger: PredictEditsRequestTrigger,
+}
+
+#[derive(Default, Debug, Clone, Copy, Serialize, Deserialize)]
+pub enum PredictEditsRequestTrigger {
+    Diagnostics,
+    Cli,
+    #[default]
+    Other,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]

crates/cloud_llm_client/src/predict_edits_v3.rs

@@ -9,7 +9,7 @@ use std::{
 use strum::EnumIter;
 use uuid::Uuid;
 
-use crate::PredictEditsGitInfo;
+use crate::{PredictEditsGitInfo, PredictEditsRequestTrigger};
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct PlanContextRetrievalRequest {
@@ -53,6 +53,8 @@ pub struct PredictEditsRequest {
     pub prompt_max_bytes: Option<usize>,
     #[serde(default)]
     pub prompt_format: PromptFormat,
+    #[serde(default)]
+    pub trigger: PredictEditsRequestTrigger,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]