Record externally completed agent config imports (#34981)

## Why

Clients that complete an external agent config import outside the app server need a way to include the result in import history.

## What changed

- Add `externalAgentConfig/import/recordHistory` to persist completed item results and return a generated import ID.
- Store the optional provider ID for regular imports and expose it when reading import history.
- Update the generated JSON and TypeScript protocol schemas for the new request, response, and history field.

## Testing

- Cover recording and reading an externally completed import through the app-server protocol.
- Cover provider ID persistence and updates in the state runtime.

GitOrigin-RevId: 935401e899ec9eeb38f54c182e45a16642411deb

codex-rs/app-server-protocol/src/protocol/v2/config.rs

@@ -741,8 +741,8 @@ pub struct ExternalAgentConfigImportParams {
     /// Optional identifier for the product that initiated the import.
     #[ts(optional = nullable)]
     pub source: Option<String>,
-    /// Opaque provider identifier supplied by the caller for analytics attribution. This does not
-    /// select the migration source.
+    /// Opaque provider identifier supplied by the caller for analytics attribution and import
+    /// history display. This does not select the migration source.
     #[ts(optional = nullable)]
     pub provider_id: Option<String>,
     /// Migration-source selector used to produce the migration items. Pass the same value to
@@ -790,11 +790,29 @@ pub struct ExternalAgentConfigImportTypeResult {
     pub failures: Vec<ExternalAgentConfigImportItemTypeFailure>,
 }
 
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ExternalAgentConfigImportHistoryRecordParams {
+    /// Opaque provider identifier for the externally completed import.
+    pub provider_id: String,
+    /// Completed results grouped by imported item type.
+    pub item_type_results: Vec<ExternalAgentConfigImportTypeResult>,
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
+#[serde(rename_all = "camelCase")]
+#[ts(export_to = "v2/")]
+pub struct ExternalAgentConfigImportHistoryRecordResponse {
+    pub import_id: String,
+}
+
 #[derive(Serialize, Deserialize, Debug, Clone, PartialEq, Eq, JsonSchema, TS)]
 #[serde(rename_all = "camelCase")]
 #[ts(export_to = "v2/")]
 pub struct ExternalAgentConfigImportHistory {
     pub import_id: String,
+    pub provider_id: Option<String>,
     pub completed_at_ms: i64,
     pub successes: Vec<ExternalAgentConfigImportItemTypeSuccess>,
     pub failures: Vec<ExternalAgentConfigImportItemTypeFailure>,