feat: Add header registry infrastructure

- Create TypeScript interfaces for header providers
- Implement header registry with priority-based ordering
- Add network client adapters that integrate with the registry
- Add comprehensive unit tests

Co-Authored-By: Claude <noreply@anthropic.com>

src/examples/headerProviderExample.ts

@@ -0,0 +1,133 @@
+/**
+ * Example of how extensions can register header providers
+ * This file demonstrates the header registration API for extension developers
+ */
+import { headerRegistry } from '@/services/headerRegistry'
+import type {
+  HeaderMap,
+  HeaderProviderContext,
+  IHeaderProvider
+} from '@/types/headerTypes'
+
+/**
+ * Example 1: Simple static header provider
+ */
+class StaticHeaderProvider implements IHeaderProvider {
+  provideHeaders(_context: HeaderProviderContext): HeaderMap {
+    return {
+      'X-Extension-Name': 'my-extension',
+      'X-Extension-Version': '1.0.0'
+    }
+  }
+}
+
+/**
+ * Example 2: Dynamic header provider that adds headers based on the request
+ */
+class DynamicHeaderProvider implements IHeaderProvider {
+  async provideHeaders(context: HeaderProviderContext): Promise<HeaderMap> {
+    const headers: HeaderMap = {}
+
+    // Add different headers based on the URL
+    if (context.url.includes('/api/')) {
+      headers['X-API-Version'] = 'v2'
+    }
+
+    // Add headers based on request method
+    if (context.method === 'POST' || context.method === 'PUT') {
+      headers['X-Request-ID'] = () => crypto.randomUUID()
+    }
+
+    // Add timestamp header
+    headers['X-Timestamp'] = () => new Date().toISOString()
+
+    return headers
+  }
+}
+
+/**
+ * Example 3: Auth token provider
+ */
+class AuthTokenProvider implements IHeaderProvider {
+  private getToken(): string | null {
+    // This could retrieve a token from storage, state, etc.
+    return localStorage.getItem('auth-token')
+  }
+
+  provideHeaders(_context: HeaderProviderContext): HeaderMap {
+    const token = this.getToken()
+
+    if (token) {
+      return {
+        Authorization: `Bearer ${token}`
+      }
+    }
+
+    return {}
+  }
+}
+
+/**
+ * Example of how to register providers in an extension
+ */
+export function setupHeaderProviders() {
+  // Register a simple static provider
+  const staticRegistration = headerRegistry.registerHeaderProvider(
+    new StaticHeaderProvider()
+  )
+
+  // Register a dynamic provider with higher priority
+  const dynamicRegistration = headerRegistry.registerHeaderProvider(
+    new DynamicHeaderProvider(),
+    { priority: 10 }
+  )
+
+  // Register an auth provider that only applies to API endpoints
+  const authRegistration = headerRegistry.registerHeaderProvider(
+    new AuthTokenProvider(),
+    {
+      priority: 20, // Higher priority to override other auth headers
+      filter: (context) => context.url.includes('/api/')
+    }
+  )
+
+  // Return cleanup function for when extension is unloaded
+  return () => {
+    staticRegistration.dispose()
+    dynamicRegistration.dispose()
+    authRegistration.dispose()
+  }
+}
+
+/**
+ * Example of a provider that integrates with a cloud service
+ */
+export class CloudServiceHeaderProvider implements IHeaderProvider {
+  constructor(
+    private apiKey: string,
+    private workspaceId: string
+  ) {}
+
+  async provideHeaders(context: HeaderProviderContext): Promise<HeaderMap> {
+    // Only add headers for requests to the cloud service
+    if (!context.url.includes('cloud.comfyui.com')) {
+      return {}
+    }
+
+    return {
+      'X-API-Key': this.apiKey,
+      'X-Workspace-ID': this.workspaceId,
+      'X-Client-Version': '1.0.0',
+      'X-Session-ID': async () => {
+        // Could fetch or generate session ID asynchronously
+        const sessionId = await this.getOrCreateSessionId()
+        return sessionId
+      }
+    }
+  }
+
+  private async getOrCreateSessionId(): Promise<string> {
+    // Simulate async session creation
+    return 'session-' + Date.now()
+  }
+}