docs: add framework leak examples

- Add UserWithFrameworks.ts example showing framework leaks in domain
- Add examples/bad/ directory with anti-pattern demonstrations
- Demonstrate common mistakes: Prisma in domain, Express types, etc.

packages/guardian/examples/bad-architecture/framework-leaks/UserWithFrameworks.ts

@@ -0,0 +1,23 @@
+/**
+ * BAD EXAMPLE: Framework Leaks in Domain Layer
+ * This file should be in a domain layer structure to be detected
+ */
+
+import { PrismaClient } from "@prisma/client"
+import { Request, Response } from "express"
+import axios from "axios"
+
+export class UserWithFrameworkLeaks {
+    private prisma = new PrismaClient()
+
+    async save(): Promise<void> {
+        await this.prisma.user.create({
+            data: { id: "1", email: "test@example.com" },
+        })
+    }
+
+    async validateEmail(email: string): Promise<boolean> {
+        const response = await axios.post("https://api.validator.com/email", { email })
+        return response.data.valid
+    }
+}

packages/guardian/examples/bad/FrameworkLeak.ts

@@ -0,0 +1,58 @@
+/**
+ * BAD EXAMPLE: Framework Leak in Domain Layer
+ *
+ * This file violates Clean Architecture by importing framework-specific packages
+ * directly into the domain layer, creating tight coupling.
+ *
+ * Issues:
+ * 1. Direct Prisma dependency in domain (ORM leak)
+ * 2. Express types in domain (web framework leak)
+ * 3. Axios in domain (HTTP client leak)
+ *
+ * Fix: Use interfaces in domain, implement in infrastructure
+ */
+
+import { PrismaClient } from "@prisma/client"
+import { Request, Response } from "express"
+import axios from "axios"
+
+// ❌ Bad: Domain entity with database dependency
+export class UserWithPrisma {
+    private prisma = new PrismaClient()
+
+    constructor(
+        private id: string,
+        private email: string,
+    ) {}
+
+    async save(): Promise<void> {
+        await this.prisma.user.create({
+            data: { id: this.id, email: this.email },
+        })
+    }
+
+    async find(id: string): Promise<UserWithPrisma | null> {
+        const user = await this.prisma.user.findUnique({ where: { id } })
+        return user ? new UserWithPrisma(user.id, user.email) : null
+    }
+}
+
+// ❌ Bad: Domain service with HTTP dependency
+export class UserServiceWithAxios {
+    async validateEmail(email: string): Promise<boolean> {
+        const response = await axios.post("https://api.validator.com/email", { email })
+        return response.data.valid
+    }
+}
+
+// ❌ Bad: Domain value object with web framework dependency
+export class EmailRequest {
+    constructor(
+        public req: Request,
+        public res: Response,
+    ) {}
+
+    getEmail(): string {
+        return this.req.body.email
+    }
+}