docs: add error guide for NG05101

Adds a new error reference page for NG05101 (NO_PLUGIN_FOR_EVENT),
which is thrown when no registered EventManagerPlugin supports the
event name passed to addEventListener. The page covers the two common
causes: a typo in the event binding and a missing plugin provider.

adev/src/content/reference/errors/NG05101.md

@@ -0,0 +1,26 @@
+# No event manager plugin found for event
+
+This error occurs when Angular tries to set up a listener for an event but none of the registered event manager plugins recognizes the event name.
+
+## Debugging the error
+
+The error message includes the unrecognized event name, which is usually enough to spot the problem. The most common cause is a typo in the event binding:
+
+```html
+<!-- 'keyup.ente' is not recognized -->
+<input (keyup.ente)="onEnter()" />
+
+<!-- Correct -->
+<input (keyup.enter)="onEnter()" />
+```
+
+If the event name is intentional and belongs to a third-party plugin (for example, a Hammer.js gesture event), make sure the plugin is provided via the `EVENT_MANAGER_PLUGINS` token:
+
+```typescript
+import {ApplicationConfig} from '@angular/core';
+import {EVENT_MANAGER_PLUGINS} from '@angular/platform-browser';
+
+export const appConfig: ApplicationConfig = {
+  providers: [{provide: EVENT_MANAGER_PLUGINS, useClass: MyCustomPlugin, multi: true}],
+};
+```

goldens/public-api/platform-browser/errors.api.md

@@ -13,7 +13,7 @@ export const enum RuntimeErrorCode {
     // (undocumented)
     HYDRATION_CONFLICTING_FEATURES = 5001,
     // (undocumented)
-    NO_PLUGIN_FOR_EVENT = 5101,
+    NO_PLUGIN_FOR_EVENT = -5101,
     // (undocumented)
     ROOT_NODE_NOT_FOUND = -5104,
     // (undocumented)

packages/platform-browser/src/errors.ts

@@ -16,7 +16,7 @@ export const enum RuntimeErrorCode {
 
   // misc errors (5100-5200 range)
   BROWSER_MODULE_ALREADY_LOADED = 5100,
-  NO_PLUGIN_FOR_EVENT = 5101,
+  NO_PLUGIN_FOR_EVENT = -5101,
   UNSUPPORTED_EVENT_TARGET = 5102,
   TESTABILITY_NOT_FOUND = 5103,
   ROOT_NODE_NOT_FOUND = -5104,

packages/platform-browser/test/dom/events/event_manager_spec.ts

@@ -60,7 +60,7 @@ import type {} from 'zone.js';
       const plugin = new FakeEventManagerPlugin(doc, ['dblclick']);
       const manager = new EventManager([plugin], new FakeNgZone());
       expect(() => manager.addEventListener(element, 'click', null!)).toThrowError(
-        'NG05101: No event manager plugin found for event click',
+        'NG05101: No event manager plugin found for event click. Find more at https://next.angular.dev/errors/NG05101',
       );
     });