Emit analytics for remote plugin installs (#20267)

## Summary

- emit `codex_plugin_installed` after a remote plugin install succeeds
- keep local installs unchanged, but let remote installs override the
analytics `plugin_id` with the backend remote plugin id
(`plugins~Plugin_...`)
- preserve the local/display identity in `plugin_name` and
`marketplace_name`, plus capability metadata from the installed bundle
- add regression coverage for local install analytics, remote install
analytics, and analytics id override serialization

## Testing

- `just fmt`
- `cargo test -p codex-analytics`
- `cargo test -p codex-app-server`

codex-rs/analytics/src/analytics_client_tests.rs

@@ -1496,6 +1496,25 @@ fn plugin_management_event_serializes_expected_shape() {
     );
 }
 
+#[test]
+fn plugin_management_event_can_use_remote_plugin_id_override() {
+    let mut plugin = sample_plugin_metadata();
+    plugin.remote_plugin_id = Some("plugins~Plugin_remote".to_string());
+    let event = TrackEventRequest::PluginInstalled(CodexPluginEventRequest {
+        event_type: "codex_plugin_installed",
+        event_params: codex_plugin_metadata(plugin),
+    });
+
+    let payload = serde_json::to_value(&event).expect("serialize plugin installed event");
+
+    assert_eq!(
+        payload["event_params"]["plugin_id"],
+        "plugins~Plugin_remote"
+    );
+    assert_eq!(payload["event_params"]["plugin_name"], "sample");
+    assert_eq!(payload["event_params"]["marketplace_name"], "test");
+}
+
 #[test]
 fn hook_run_event_serializes_expected_shape() {
     let tracking = TrackEventsContext {
@@ -2482,6 +2501,7 @@ async fn turn_completed_without_started_notification_emits_null_started_at() {
 fn sample_plugin_metadata() -> PluginTelemetryMetadata {
     PluginTelemetryMetadata {
         plugin_id: PluginId::parse("sample@test").expect("valid plugin id"),
+        remote_plugin_id: None,
         capability_summary: Some(PluginCapabilitySummary {
             config_name: "sample@test".to_string(),
             display_name: "sample".to_string(),