fix: restore double quotes style in config.example.yaml for consistency and readability

config.example.yaml

@@ -1,6 +1,6 @@
 # Server host/interface to bind to. Default is empty ("") to bind all interfaces (IPv4 + IPv6).
 # Use "127.0.0.1" or "localhost" to restrict access to local machine only.
-host: ''
+host: ""
 
 # Server port
 port: 8317
@@ -8,8 +8,8 @@ port: 8317
 # TLS settings for HTTPS. When enabled, the server listens with the provided certificate and key.
 tls:
   enable: false
-  cert: ''
-  key: ''
+  cert: ""
+  key: ""
 
 # Management API settings
 remote-management:
@@ -20,22 +20,22 @@ remote-management:
   # Management key. If a plaintext value is provided here, it will be hashed on startup.
   # All management requests (even from localhost) require this key.
   # Leave empty to disable the Management API entirely (404 for all /v0/management routes).
-  secret-key: ''
+  secret-key: ""
 
   # Disable the bundled management control panel asset download and HTTP route when true.
   disable-control-panel: false
 
   # GitHub repository for the management control panel. Accepts a repository URL or releases API URL.
-  panel-github-repository: 'https://github.com/router-for-me/Cli-Proxy-API-Management-Center'
+  panel-github-repository: "https://github.com/router-for-me/Cli-Proxy-API-Management-Center"
 
 # Authentication directory (supports ~ for home directory)
-auth-dir: '~/.cli-proxy-api'
+auth-dir: "~/.cli-proxy-api"
 
 # API keys for authentication
 api-keys:
-  - 'your-api-key-1'
-  - 'your-api-key-2'
-  - 'your-api-key-3'
+  - "your-api-key-1"
+  - "your-api-key-2"
+  - "your-api-key-3"
 
 # Enable debug logging
 debug: false
@@ -43,7 +43,7 @@ debug: false
 # Enable pprof HTTP debug server (host:port). Keep it bound to localhost for safety.
 pprof:
   enable: false
-  addr: '127.0.0.1:8316'
+  addr: "127.0.0.1:8316"
 
 # When true, disable high-overhead HTTP middleware features to reduce per-request memory usage under high concurrency.
 commercial-mode: false
@@ -63,7 +63,7 @@ error-logs-max-files: 10
 usage-statistics-enabled: false
 
 # Proxy URL. Supports socks5/http/https protocols. Example: socks5://user:pass@192.168.1.1:1080/
-proxy-url: ''
+proxy-url: ""
 
 # When true, unprefixed model requests only use credentials without a prefix (except when prefix == model name).
 force-model-prefix: false
@@ -89,7 +89,7 @@ quota-exceeded:
 
 # Routing strategy for selecting credentials when multiple match.
 routing:
-  strategy: 'round-robin' # round-robin (default), fill-first
+  strategy: "round-robin" # round-robin (default), fill-first
 
 # When true, enable authentication for the WebSocket API (/v1/ws).
 ws-auth: false