chore: plugin/uninstall endpoint (#14111)

add `plugin/uninstall` app-server endpoint to fully rm plugin from
plugins cache dir and rm entry from user config file.

plugin-enablement is session-scoped, so uninstalls are only picked up in
new sessions (like installs).

added tests.

codex-rs/app-server/src/codex_message_processor.rs

@@ -90,6 +90,8 @@ use codex_app_server_protocol::PluginListResponse;
 use codex_app_server_protocol::PluginMarketplaceEntry;
 use codex_app_server_protocol::PluginSource;
 use codex_app_server_protocol::PluginSummary;
+use codex_app_server_protocol::PluginUninstallParams;
+use codex_app_server_protocol::PluginUninstallResponse;
 use codex_app_server_protocol::ProductSurface as ApiProductSurface;
 use codex_app_server_protocol::RequestId;
 use codex_app_server_protocol::ReviewDelivery as ApiReviewDelivery;
@@ -217,6 +219,7 @@ use codex_core::plugins::MarketplaceError;
 use codex_core::plugins::MarketplacePluginSourceSummary;
 use codex_core::plugins::PluginInstallError as CorePluginInstallError;
 use codex_core::plugins::PluginInstallRequest;
+use codex_core::plugins::PluginUninstallError as CorePluginUninstallError;
 use codex_core::plugins::load_plugin_apps;
 use codex_core::read_head_for_summary;
 use codex_core::read_session_meta_line;
@@ -711,6 +714,10 @@ impl CodexMessageProcessor {
                 self.plugin_install(to_connection_request_id(request_id), params)
                     .await;
             }
+            ClientRequest::PluginUninstall { request_id, params } => {
+                self.plugin_uninstall(to_connection_request_id(request_id), params)
+                    .await;
+            }
             ClientRequest::TurnStart { request_id, params } => {
                 self.turn_start(
                     to_connection_request_id(request_id),
@@ -5516,6 +5523,57 @@ impl CodexMessageProcessor {
         }
     }
 
+    async fn plugin_uninstall(
+        &self,
+        request_id: ConnectionRequestId,
+        params: PluginUninstallParams,
+    ) {
+        let plugins_manager = self.thread_manager.plugins_manager();
+
+        match plugins_manager.uninstall_plugin(params.plugin_id).await {
+            Ok(()) => {
+                self.clear_plugin_related_caches();
+                self.outgoing
+                    .send_response(request_id, PluginUninstallResponse {})
+                    .await;
+            }
+            Err(err) => {
+                if err.is_invalid_request() {
+                    self.send_invalid_request_error(request_id, err.to_string())
+                        .await;
+                    return;
+                }
+
+                match err {
+                    CorePluginUninstallError::Config(err) => {
+                        self.send_internal_error(
+                            request_id,
+                            format!("failed to clear plugin config: {err}"),
+                        )
+                        .await;
+                    }
+                    CorePluginUninstallError::Join(err) => {
+                        self.send_internal_error(
+                            request_id,
+                            format!("failed to uninstall plugin: {err}"),
+                        )
+                        .await;
+                    }
+                    CorePluginUninstallError::Store(err) => {
+                        self.send_internal_error(
+                            request_id,
+                            format!("failed to uninstall plugin: {err}"),
+                        )
+                        .await;
+                    }
+                    CorePluginUninstallError::InvalidPluginId(_) => {
+                        unreachable!("invalid plugin ids are handled above");
+                    }
+                }
+            }
+        }
+    }
+
     async fn turn_start(
         &self,
         request_id: ConnectionRequestId,