fix: add transitive @types deps for raw .ts consumers

[enitrat]

Summary

• Moves @types/react-reconciler from devDependencies to dependencies
• Adds @types/react-dom to dependencies
• Adds a README note about skipLibCheck: true for consumers

Problem

Smithers ships raw TypeScript source (all exports point to ./src/*.ts files). When consumers type-check their project, TypeScript processes Smithers' source and encounters missing type declarations:

node_modules/smithers-orchestrator/src/components.ts(2,38): error TS7016:
  Could not find a declaration file for module 'react-dom/server'.
node_modules/smithers-orchestrator/src/dom/renderer.ts(1,24): error TS7016:
  Could not find a declaration file for module 'react-reconciler'.

skipLibCheck: true only skips .d.ts files — it has no effect on .ts files in node_modules. Moving the @types/* packages to dependencies ensures they're installed transitively.

This is a minimal fix. A more complete solution would be to ship compiled .js + .d.ts output so skipLibCheck works as expected.

Test plan

• bun install succeeds
• bun run typecheck passes
• Consumer project no longer sees TS7016 errors from Smithers' internals
• @types/react-dom and @types/react-reconciler are present in consumer's node_modules after installing Smithers