Add TopoJSON administrative boundaries (comuni, province, regioni, ISTAT districts)

[aborruso]

Feature Request

Expose Italian administrative boundary files in TopoJSON format as MCP resources or tool outputs.

Boundaries to include

• Comuni (municipalities)
• Province (provinces)
• Regioni (regions)
• ISTAT district subdivisions

Motivation

Users querying CKAN portals often need to cross-reference data with geographic boundaries. Having these available via MCP would allow spatial analysis without external lookups.

Possible approaches

1. Static TopoJSON files bundled or hosted, referenced via MCP resources
2. Tool that fetches boundaries from a canonical source (e.g., ISTAT or OpenData)
3. Integration with existing ckan_datastore_search to filter by geometry