Add remote models feature flag (#7648)

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codex-rs/protocol/src/protocol.rs

@@ -1348,7 +1348,7 @@ pub struct ReviewLineRange {
     pub end: u32,
 }
 
-#[derive(Debug, Clone, Copy, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
+#[derive(Debug, Clone, Copy, Display, Deserialize, Serialize, PartialEq, Eq, JsonSchema, TS)]
 #[serde(rename_all = "snake_case")]
 pub enum ExecCommandSource {
     Agent,