docs: refactor documentation and upgrade to Node.js 24

This commit upgrades the project to Node.js 24 (LTS) and performs a major refactoring of the documentation to support both advanced users and AI-based automation (MCP).

Changes:
- Environment & CI/CD:
  - Set Node.js version to >=24 in package.json and .nvmrc.
  - Updated Dockerfile to use Node 24 base image.
  - Updated @types/node to ^24.10.9.
- Documentation:
  - Refactored README.md with comprehensive technical reference, configuration details, and Zabbix-to-GraphQL mapping.
  - Created docs/howtos/cookbook.md with practical recipes for common tasks and AI test generation.
  - Updated docs/howtos/mcp.md to emphasize GraphQL's advantages for AI agents and Model Context Protocol.
  - Added readme.improvement.plan.md to track documentation evolution.
  - Enhanced all how-to guides with improved cross-references and up-to-date information.
- Guidelines:
  - Updated .junie/guidelines.md with Node 24 requirements and enhanced commit message standards (Conventional Commits 1.0.0).
- Infrastructure & Code:
  - Updated docker-compose.yml with Apollo MCP server integration.
  - Refined configuration and schema handling in src/api/ and src/datasources/.
  - Synchronized generated TypeScript types with schema updates.

codegen.ts

@@ -16,8 +16,7 @@ const config: CodegenConfig = {
                 declarationKind: 'interface'
             }
         }
-    },
-    watch: true
+    }
 };
 
 export default config;