feat: add bun-fullstack agent and update skills

.agent/skills/tech-stack/elysiajs/plugins/bearer.md

@@ -0,0 +1,30 @@
+# Bearer
+Plugin for Elysia for retrieving the Bearer token.
+
+## Installation
+```bash
+bun add @elysiajs/bearer
+```
+
+## Basic Usage
+```typescript twoslash
+import { Elysia } from 'elysia'
+import { bearer } from '@elysiajs/bearer'
+
+const app = new Elysia()
+    .use(bearer())
+    .get('/sign', ({ bearer }) => bearer, {
+        beforeHandle({ bearer, set, status }) {
+            if (!bearer) {
+                set.headers[
+                    'WWW-Authenticate'
+                ] = `Bearer realm='sign', error="invalid_request"`
+
+                return status(400, 'Unauthorized')
+            }
+        }
+    })
+    .listen(3000)
+```
+
+This plugin is for retrieving a Bearer token specified in RFC6750