Remove embedded OAuth implementation and flatten directory structure

Simplified the repository to have a single OAuth pattern with separate auth and MCP servers at the top level. Preserved embedded OAuth documentation as an alternative pattern.

auth-server/package.json

@@ -0,0 +1,43 @@
+{
+  "name": "mcp-server-feature-reference-external-auth-server",
+  "version": "0.1.0",
+  "description": "MCP Feature Reference Server - Standalone Authorization Server",
+  "type": "module",
+  "main": "dist/index.js",
+  "scripts": {
+    "start": "node dist/index.js",
+    "dev": "tsx watch --inspect src/index.ts",
+    "dev:break": "tsx --inspect-brk watch src/index.ts",
+    "build": "tsc && npm run copy-static",
+    "copy-static": "mkdir -p dist/static && cp -r src/static/* dist/static/",
+    "lint": "eslint src/",
+    "typecheck": "tsc --noEmit",
+    "test": "NODE_OPTIONS=--experimental-vm-modules jest"
+  },
+  "dependencies": {
+    "@modelcontextprotocol/sdk": "^1.15.1",
+    "@redis/client": "^1.6.0",
+    "cors": "^2.8.5",
+    "dotenv": "^16.4.7",
+    "express": "^4.21.2",
+    "express-rate-limit": "^8.0.1",
+    "raw-body": "^3.0.0"
+  },
+  "devDependencies": {
+    "@eslint/js": "^9.15.0",
+    "@types/content-type": "^1.1.8",
+    "@types/cors": "^2.8.17",
+    "@types/express": "^5.0.0",
+    "@types/jest": "^29.5.14",
+    "@types/node": "^22.10.0",
+    "jest": "^29.7.0",
+    "ts-jest": "^29.2.5",
+    "tsx": "^4.19.2",
+    "typescript": "^5.7.2",
+    "typescript-eslint": "^8.18.0"
+  },
+  "overrides": {
+    "@types/express": "^5.0.0",
+    "@types/express-serve-static-core": "^5.0.2"
+  }
+}