docs: enhance documentation and automate MCP setup

This commit introduces several improvements to the project's documentation,
roadmap, and AI agent integration (MCP).

Key changes:
- Created and styled roadmap.md to track project milestones and future plans.
- Updated .junie/guidelines.md with strict documentation style standards.
- Automated GraphQL schema concatenation for the MCP server using a schema-gen init-container.
- Updated MCP setup recipes in cookbook.md and mcp.md to reflect the new automation.
- Added .ai/mcp/mcp.json for connecting to existing MCP services via HTTP.
- Improved development workflow by updating package.json to watch .graphql files.
- Cleaned up the root directory by moving schema.graphql to .gitignore and removing redundant files.
- Standardized visual style and formatting across all markdown files.

.ai/mcp/mcp.json

@@ -0,0 +1,7 @@
+{
+  "mcpServers": {
+    "zabbix-graphql": {
+      "url": "http://localhost:3000/mcp"
+    }
+  }
+}