chore(zendesk): update OAuth scope for full access

Expanded OAuth scope to "read write" in configurations and documentation to enable full tool access for Zendesk MCP server, allowing write operations instead of read-only access.

Author: winromulus

docs/libraries/zendesk-mcp-server.md

@@ -107,7 +107,7 @@ server behavior lives under `Mcp`. All keys are environment-overridable (`__` ma
       "OAuth": {                        // OAuth 2.0 client_credentials (confidential client)
         "ClientId": "***",
         "ClientSecret": "***",
-        "Scope": "read"                 // use "read write" to enable the write tools
+        "Scope": "read write"           // full tool surface; drop "write" for a read-only client
       }
     }
   },

src/ES.FX.Zendesk.MCP.Host/appsettings.json

@@ -36,7 +36,7 @@
       "OAuth": {
         "ClientId": "",
         "ClientSecret": "",
-        "Scope": "read"
+        "Scope": "read write"
       },
       "Settings": {
         "HealthChecks": { "Enabled": true },