fireclass-core v2.0.9

@dharayush7/fireclass-core v2.0.9 is a documentation and npm
discovery release. Runtime behavior remains compatible with v2.0.8.

What changed

Rebuilt the README from the complete Fireclass website core, concepts, and
testing documentation.
Added the Fireclass logo and direct links to the API, concepts, testing,
GitHub, and npm.
Documented the complete model lifecycle, query operators, decorators, adapter
capabilities, validation pipeline, error hierarchy, and FakeAdapter.
Clarified that Subcollection metadata does not yet resolve nested paths.
Removed npm, license, and type shield badges.
Expanded the npm description and keywords for typed Firestore models, ODM,
adapters, validation, query building, and in-memory testing.
Added changelog and release notes to the published package contents.

No exports, types, runtime behavior, peer dependency ranges, or adapter
contracts changed.

npm run typecheck
npm test
npm run build
npm pack --dry-run