Implement clean Moqui-centric MCP v2.0 using built-in JSON-RPC

- Replace custom REST API with Moqui's native /rpc/json endpoint
- Implement MCP methods as standard Moqui services with allow-remote='true'
- Remove unnecessary custom layers (webapp, screens, custom JSON-RPC handler)
- Direct service-to-tool mapping for maximum simplicity
- Leverage Moqui's built-in authentication, permissions, and audit logging
- Comprehensive client examples for Python, JavaScript, and cURL
- Complete documentation with architecture overview and usage patterns

Key Changes:
- service/McpServices.xml: MCP methods as standard Moqui services
- component.xml: Minimal configuration, no custom webapp
- AGENTS.md: Updated for Moqui-centric approach
- entity/, data/: Minimal extensions, leverage built-in entities
- Removed: mcp.rest.xml, screen/ directory (unnecessary complexity)

This demonstrates the power of Moqui's built-in JSON-RPC support
for clean, maintainable MCP integration.

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This software is in the public domain under CC0 1.0 Universal plus a 
+     Grant of Patent License.
+
+     To the extent possible under law, the author(s) have dedicated all
+     copyright and related and neighboring rights to this software to the
+     public domain worldwide. This software is distributed without any warranty.
+
+     You should have received a copy of the CC0 Public Domain Dedication
+     along with this software (see the LICENSE.md file). If not, see
+     <https://creativecommons.org/publicdomain/zero/1.0/>. -->
+
+<component xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="http://moqui.org/xsd/component-definition-3.xsd">
+
+    <!-- No dependencies - uses only core framework -->
+
+    <entity-factory load-path="entity/" />
+    <service-factory load-path="service/" />
+    
+    <!-- Load seed data -->
+    <entity-factory load-data="data/McpSecuritySeedData.xml" />
+
+</component>
\ No newline at end of file

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This software is in the public domain under CC0 1.0 Universal plus a 
+     Grant of Patent License.
+
+     To the extent possible under law, the author(s) have dedicated all
+     copyright and related and neighboring rights to this software to the
+     public domain worldwide. This software is distributed without any warranty.
+
+     You should have received a copy of the CC0 Public Domain Dedication
+     along with this software (see the LICENSE.md file). If not, see
+     <https://creativecommons.org/publicdomain/zero/1.0/>. -->
+
+<entity-facade-xml xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:noNamespaceSchemaLocation="http://moqui.org/xsd/entity-facade-3.xsd">
+
+    <!-- MCP User Group -->
+    <moqui.security.UserGroup userGroupId="McpUser" description="MCP Server Users"/>
+    
+    <!-- MCP Artifact Groups -->
+    <moqui.security.ArtifactGroup artifactGroupId="McpRestPaths" description="MCP REST Paths"/>
+    <moqui.security.ArtifactGroup artifactGroupId="McpServices" description="MCP Services"/>
+    
+    <!-- MCP Artifact Group Members -->
+    <moqui.security.ArtifactGroupMember artifactGroupId="McpRestPaths" artifactName="/rest/s1/mcp-2" artifactTypeEnumId="AT_REST_PATH"/>
+    <moqui.security.ArtifactGroupMember artifactGroupId="McpServices" artifactName="org.moqui.mcp.*" artifactTypeEnumId="AT_SERVICE"/>
+    
+    <!-- MCP Artifact Authz -->
+    <moqui.security.ArtifactAuthz userGroupId="McpUser" artifactGroupId="McpRestPaths" authzTypeEnumId="AUTHZT_ALLOW" authzActionEnumId="AUTHZA_ALL"/>
+    <moqui.security.ArtifactAuthz userGroupId="McpUser" artifactGroupId="McpServices" authzTypeEnumId="AUTHZT_ALLOW" authzActionEnumId="AUTHZA_ALL"/>
+    
+    <!-- Add admin user to MCP user group for testing -->
+    <moqui.security.UserGroupMember userGroupId="McpUser" userId="ADMIN" fromDate="2025-01-01 00:00:00.000"/>
+
+</entity-facade-xml>
\ No newline at end of file

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- This software is in the public domain under CC0 1.0 Universal plus a 
+     Grant of Patent License.
+
+     To the extent possible under law, the author(s) have dedicated all
+     copyright and related and neighboring rights to this software to the
+     public domain worldwide. This software is distributed without any warranty.
+
+     You should have received a copy of the CC0 Public Domain Dedication
+     along with this software (see the LICENSE.md file). If not, see
+     <https://creativecommons.org/publicdomain/zero/1.0/>. -->
+
+<entities xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+          xsi:noNamespaceSchemaLocation="http://moqui.org/xsd/entity-definition-3.xsd">
+
+    <!-- No custom entities needed - use Moqui's built-in entities directly -->
+    <!-- MCP uses standard Moqui authentication, audit logging, and permissions -->
+
+</entities>
\ No newline at end of file