feat(rah-light): remove unused supabaseTokenRegistry

- Delete src/services/context/supabaseTokenRegistry.ts (stub for private version, not imported)
- Keep requestContext.ts (used by workflow executor, middleware)
- Keep autoContext.ts (used by workflow API and tools)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/services/context/supabaseTokenRegistry.ts

@@ -1,22 +0,0 @@
-/**
- * Stub for SupabaseTokenRegistry - not used in open source version
- * The private version uses this for backend API authentication.
- * In open source mode, all API calls go directly to OpenAI/Anthropic.
- */
-export class SupabaseTokenRegistry {
-  static async get(_key: string): Promise<string | null> {
-    return null;
-  }
-  
-  static getLast(_key: string): string | null {
-    return null;
-  }
-  
-  static set(_key: string, _value: string): void {
-    // No-op in OS version
-  }
-  
-  static delete(_key: string): void {
-    // No-op in OS version
-  }
-}