Remove remote plugin uninstall prefix gate (#20722)

## Summary

Remove the hardcoded remote plugin ID prefix allow-list from app-server
uninstall routing. IDs that do not parse as local `plugin@marketplace`
IDs now flow through the remote uninstall path, where the existing
remote ID safety validation still rejects empty IDs, spaces, slashes,
and other unsafe characters before URL/cache use.

## Why

Plugin-service owns the backend remote plugin ID contract. Codex should
not require remote IDs to start with the local hardcoded prefixes
`plugins~`, `plugins_`, `app_`, `asdk_app_`, or `connector_`, because
newer backend ID families could otherwise be rejected before
plugin-service sees the request.

## Validation

- `just fmt`
- `cargo test -p codex-app-server plugin_uninstall`
- `just fix -p codex-app-server`
- `git diff --check`

codex-rs/app-server/src/request_processors/plugins.rs

@@ -1015,13 +1015,11 @@ impl PluginRequestProcessor {
     ) -> Result<PluginUninstallResponse, JSONRPCErrorError> {
         let PluginUninstallParams { plugin_id } = params;
         if codex_plugin::PluginId::parse(&plugin_id).is_err()
-            && !is_valid_remote_uninstall_plugin_id(&plugin_id)
+            && !is_valid_remote_plugin_id(&plugin_id)
         {
-            return Err(invalid_request(
-                "invalid plugin id: expected a local plugin id in the form `plugin@marketplace` or a remote plugin id starting with `plugins~`, `plugins_`, `app_`, `asdk_app_`, or `connector_`",
-            ));
+            return Err(invalid_request("invalid remote plugin id"));
         }
-        if is_valid_remote_uninstall_plugin_id(&plugin_id) {
+        if is_valid_remote_plugin_id(&plugin_id) {
             return self.remote_plugin_uninstall_response(plugin_id).await;
         }
         let plugins_manager = self.thread_manager.plugins_manager();
@@ -1148,15 +1146,6 @@ impl PluginRequestProcessor {
     }
 }
 
-fn is_valid_remote_uninstall_plugin_id(plugin_name: &str) -> bool {
-    is_valid_remote_plugin_id(plugin_name)
-        && (plugin_name.starts_with("plugins~")
-            || plugin_name.starts_with("plugins_")
-            || plugin_name.starts_with("app_")
-            || plugin_name.starts_with("asdk_app_")
-            || plugin_name.starts_with("connector_"))
-}
-
 async fn load_plugin_app_summaries(
     config: &Config,
     plugin_apps: &[codex_plugin::AppConnectorId],

codex-rs/app-server/tests/suite/v2/plugin_uninstall.rs

@@ -454,7 +454,7 @@ async fn plugin_uninstall_rejects_before_post_when_remote_detail_fetch_fails() -
 }
 
 #[tokio::test]
-async fn plugin_uninstall_rejects_invalid_plugin_id_before_remote_path() -> Result<()> {
+async fn plugin_uninstall_rejects_remote_plugin_id_with_spaces_before_network_call() -> Result<()> {
     let codex_home = TempDir::new()?;
     let server = MockServer::start().await;
     write_remote_plugin_catalog_config(
@@ -477,7 +477,7 @@ async fn plugin_uninstall_rejects_invalid_plugin_id_before_remote_path() -> Resu
     .await??;
 
     assert_eq!(err.error.code, -32600);
-    assert!(err.error.message.contains("invalid plugin id"));
+    assert!(err.error.message.contains("invalid remote plugin id"));
     wait_for_remote_plugin_request_count(
         &server,
         "POST",
@@ -512,7 +512,7 @@ async fn plugin_uninstall_rejects_invalid_remote_plugin_id_before_network_call()
     .await??;
 
     assert_eq!(err.error.code, -32600);
-    assert!(err.error.message.contains("invalid plugin id"));
+    assert!(err.error.message.contains("invalid remote plugin id"));
     wait_for_remote_plugin_request_count(
         &server,
         "POST",
@@ -546,7 +546,7 @@ async fn plugin_uninstall_rejects_empty_remote_plugin_id() -> Result<()> {
     .await??;
 
     assert_eq!(err.error.code, -32600);
-    assert!(err.error.message.contains("invalid plugin id"));
+    assert!(err.error.message.contains("invalid remote plugin id"));
 
     Ok(())
 }