feat: fix node types export, add introspection

[harbournick]

Add TypeScript types export and schema introspection for AI agents

Summary

Adds a new superdoc/types export for TypeScript type safety and a getSchemaIntrospection() function for runtime schema discovery. These features address customer requests for better tooling when building AI drafting agents (IT-37).

Changes

New superdoc/types export

• Exports TypeScript interfaces for all node and mark types
• NodeName - union of all valid node names (now expands in IDE hover tooltips)
• NodeAttrs<N> - get attribute type for a specific node
• MarkName, MarkAttrs<M> - same for marks
• Includes all specific attribute interfaces (ParagraphAttrs, TableAttrs, ImageAttrs, etc.)

import type { NodeName, NodeAttrs, ParagraphAttrs } from 'superdoc/types';

// NodeName shows all 39 node types in autocomplete
type Test = NodeAttrs<'paragraph'>; // Resolves to ParagraphAttrs

New getSchemaIntrospection() function

• Returns JSON schema summary with all nodes, marks, and their attributes
• Useful for AI agents that need schema context for prompt engineering
• Supports different modes: docx, html, text

import { getSchemaIntrospection } from 'superdoc';

const schema = await getSchemaIntrospection({ mode: 'docx' });
// Returns: { version, nodes: [...], marks: [...] }

[linear]

IT-37 Request for Zod schemas or TypeScript interfaces for node types

[caio-pizzol]

oh merged the docs PR already - lmk if we should hide it for now @harbournick

[harbournick]

🎉 This PR is included in version 1.9.0-next.1 🎉

The release is available on:

• v1.9.0-next.1
• GitHub release

Your semantic-release bot 📦🚀

[harbournick]

🎉 This PR is included in version 1.9.0 🎉

The release is available on:

• v1.9.0
• GitHub release

Your semantic-release bot 📦🚀