Validate dist package exports and typings

[damyanpetev]

Addition to #179
Will migrate the CI pipeline separately.

What

Adds a dist validation script that verifies every published package's export contract actually resolves in the built dist/ output, and wires it into CI.

How it works

scripts/validate-dist.ts iterates over each package manifest (components / dock-manager / grids), copies it to dist/package.json (exactly as the release pipeline does), and validates against the real packed output (npm pack / attw --pack), so the files allowlist is respected just like a real publish:

1. @arethetypeswrong/cli resolves the types (and their JS) for every exports entrypoint. --profile esm-only ignores the legacy node10/CJS resolution modes these ESM-only packages intentionally don't support, so a non-zero exit means a real problem. attw's own report is printed for visibility in CI and locally.
2. JS-entry backstop — attw is types-first and will still pass if a runtime .js is missing while its .d.ts resolves, so the script also confirms every JS entry point is actually in the published file set.

Changes

• scripts/validate-dist.ts — new validator (attw exit code + JS-entry check; reuses PackageJsonTypes from scripts/types.ts).
• package.json — added @arethetypeswrong/cli devDependency and a validate:dist script.
• .azure-pipelines/setup-build-test-steps.yml — new Validate dist packages step after build (runs in both CI and release pipelines).
• scripts/grids.package.json — added an explicit exports map to match the other packages, with a "./grids/*" wildcard to preserve theme CSS and the deprecated grids/combined subpath imports; legacy main/module/typings retained for back-compat.

Verification

• Passes cleanly on a correct build (exit 0, no leftover dist/package.json).
• Regression checks fail as expected: a missing .d.ts is caught by attw, and a missing .js is caught by the backstop (both exit 1).
• New script passes biome lint.

Usage

npm run build
npm run validate:dist

Additional information (check all that apply):

• Bug fix
• New functionality
• Documentation
• Demos
• CI/CD

Checklist:

• All relevant tags have been applied to this PR
• This PR includes general feature table updates in the root README.MD
• This PR includes CHANGELOG.MD updates for newly added functionality
• This PR contains breaking changes
• This PR includes behavioral changes and the feature specification has been updated with them

[rkaraivanov]

@damyanpetev

Running the validate script produces this:

  const [{ files }] = JSON.parse(
                      ^

TypeError: object is not iterable (cannot read property Symbol(Symbol.iterator))
    at packedFiles (/home/racho/work/igniteui-react/scripts/validate-dist.ts:54:23)
    at validate (/home/racho/work/igniteui-react/scripts/validate-dist.ts:82:18)
    at main (/home/racho/work/igniteui-react/scripts/validate-dist.ts:105:7)
    at <anonymous> (/home/racho/work/igniteui-react/scripts/validate-dist.ts:122:1)
    at ModuleJob.run (node:internal/modules/esm/module_job:439:25)
    at async node:internal/modules/esm/loader:643:26
    at async asyncRunEntryPointWithESMLoader (node:internal/modules/run_main:101:5)

[damyanpetev]

Odd, it ran locally, will check it. Seems like I have conflicts to resolve anyway;
Edit: and it still does

likely the npm pack --json output isn't stable across versions (-.-), will update the package resolution.

[damyanpetev]

Done, fragile exec->parse of npm pack --json, replaced with npm-packlist