v5.0.3

ci: add CI workflow and per-package API docs generation
CI (.github/workflows/ci.yml): typecheck, typecheck:examples, lint,
test, and build on every push/PR to main, matrixed across Node 22.x
(current Maintenance LTS) and 24.x (current Active LTS), with
fail-fast disabled so a real failure on one version can't be masked
by a cancellation on another. Yarn cache enabled in setup-node, keyed
off the existing committed yarn.lock.

Docs: typedoc.json + a docs script added to packages/core, web, and
native, each generating a standalone API reference from that
package's own JSDoc. A root-level docs script fans out to all three
via the existing yarn workspaces foreach pattern, matching build/
typecheck/lint/test. typedoc pinned to ^0.27.0 at the root, alongside
the rest of the shared toolchain - its peer range covers TypeScript
5.0-5.8, matching this repo's existing ^5.4.0 pin.

Also: root README gets a short "Development" section documenting all
root scripts, and docs/ output is gitignored in each package
alongside dist/.

Full Changelog: v5.0.2...v5.0.3