[docs] Document programmatic Resource static properties for MCP/OpenAPI schema authoring

[kylebernhardy]

Follow-up from #1920 / PR #1921.

static properties (a Record<string, JsonSchemaFragment>) was introduced in #1167 as the canonical class-level metadata API. PR #1921 extends it so a programmatic Resource declaring a bare static properties literal (no table-backed attributes Array) now drives rich MCP tool inputSchemas, the OpenAPI document, and the harper://schema introspection resource — types, per-property descriptions, enum/format/const, arrays, and nested objects.

The HarperFast/documentation site should document this authoring path:

• Declaring static description + static properties on a custom Resource for quality MCP/OpenAPI output (with a JSON-Schema-fragment example incl. enum/nested).
• Note that static properties uses JSON Schema vocabulary (lowercase types), distinct from Table.attributes.
• Cross-link to the MCP tool-selection metadata docs from [MCP] Quality descriptions and richer tool-payload metadata for LLM tool selection #1095/feat(mcp/openapi): quality descriptions and richer tool-payload metadata (#1095) #1167.

Needs a companion PR to HarperFast/documentation (see its AGENTS.md for versioning/mechanics).

Issue generated by kAIle (Claude Opus 4.8).