feat: add JavaScript query builder library for Dappi

[francedermaz]

What Changed?

Added dappi-query-js, a dependency-free TypeScript library that builds Dappi-compatible query strings with a fluent API. It covers filtering, sorting, pagination, search and field shaping, mapping directly to what the generated list endpoints expect (filter[...], SortBy/SortDirection, Offset/Limit, SearchTerm, fields, include).

import { createQuery, field } from 'dappi-query';

const qs = createQuery()
  .or(field('title').containsIgnoreCase('breaking'))
  .and(field('author.name').eq('john'))
  .and(field('views').gt(100))
  .sort('publishedAt', 'desc')
  .page(2, 20)
  .select('id', 'title')
  .toQueryString();

// filter[0][$or][title][$cic]=breaking&filter[1][$and][author][name][$eq]=john
//   &filter[2][$and][views][$gt]=100&Offset=20&Limit=20&SortBy=publishedAt&SortDirection=Descending&fields=id%2Ctitle

Why?

Building these query strings by hand is error-prone: the bracket syntax, operation tokens and nested field paths are easy to get wrong, and there was no client-side helper for it. This gives consumers a typed, ergonomic way to construct filters that matches the server-side parsing exactly.

Closes #351

Type of Change

• ✨ New feature (adds new functionality without breaking existing features)

How Did You Test This?

What I tested:

• 18 unit tests covering every operation, nested field paths, sorting, pagination, search, field selection, URL building and value serialization.
• A round-trip test that parses the generated query strings with a JS port of CollectionFilter, asserting each key decodes back to the intended filter (fields, operator, operation, value).
• tsc type-check and build pass with strict mode.

How to test it:

1. cd dappi-query-js
2. npm install
3. npm test

Review Checklist

• My code follows the project's style and conventions
• I've reviewed my own code for obvious issues
• I've added comments where the code might be confusing
• I've updated relevant documentation (if needed)
• I've tested my changes and they work as expected

Screenshots / Additional Context

Placed at the repo root as dappi-query-js/ (alongside CCUI.DAPPI), since packages/ is git-ignored. Ships as TypeScript with a README.md documenting the full operation set and usage. Zero runtime dependencies; vitest and typescript are the only dev dependencies.