Add support for SEP-1330 Elicitation Enums

[cliffhall]

Summary

Allows the DynamicJsonForm to render the various enum types supported by the new version of the spec (SEP-1330).

Changes Made

In DynamicJsonForm.tsx,

• Support all five enum shapes used by MCP SDK:
  • Titled single-select via oneOf/anyOf with { const, title }
  • Untitled single-select via enum
  • Titled legacy single-select with optional enumNames for labels
  • Titled multi-select via items.anyOf/oneOf
  • Untitled multi-select via items.enum
• Show field descriptions for string select fields and boolean checkboxes (consistent help text above inputs).
• Prefer schema property title for object field labels; fall back to the JSON key when missing.
• Allow top‑level form rendering for objects with properties, arrays with items, and primitive types (was overly strict before).
• Multi-select UI: sensible list size and minItems/maxItems helper text when present.
• JSON editor fallback, copy/format controls, and debounced parsing preserved.
• apply defaults for optional fields during form init

In schemaUtils.ts

• generateDefaultValue now includes optional properties that declare a default, ensuring fields like strings show their defaults on first render.

In jsonUtils.ts

• Add legacy enumNames?: string[] and array constraints minItems?/maxItems?.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Documentation update
• Refactoring (no functional changes)
• Test updates
• Build/CI improvements

Related Issues

#933

Testing

• Tested in UI mode
• Tested in CLI mode
• Tested with STDIO transport
• Tested with SSE transport
• Tested with Streamable HTTP transport
• Added/updated automated tests
• Manual testing performed

Test Results and/or Instructions

Used this PR for the Everything server which updates it Elicitation Request to have all the fields.

Checklist

• Code follows the style guidelines (ran npm run prettier-fix)
• Self-review completed
• Code is commented where necessary
• Documentation updated (README, comments, etc.)

Breaking Changes

Nope.

Additional Context

For more on the various enum types now supported by the protocol, see SEP-1330