fix: generate TypeScript declarations explicitly in build script

[Copilot]

rollup-plugin-typescript2 v0.36.0 silently stopped generating .d.ts files when paired with TypeScript 5.9.3, causing publint --strict to fail with missing ./dist/esm/index.d.ts and ./dist/cjs/index.d.cts.

Changes

• packages/live-region-element/script/build: Replace implicit declaration generation via rollup-plugin-typescript2 with an explicit tsc invocation, then copy and rename for CJS:

# Generate declarations into dist/esm
npx tsc --project tsconfig.build.json --outDir dist/esm

# Copy and rename as .d.cts for CJS consumers
for file in $(find ./dist/esm -maxdepth 1 -name '*.d.ts'); do
  basename=$(basename "$file")
  cp "$file" "./dist/cjs/${basename%.d.ts}.d.cts"
done

Original prompt

Fix the failing GitHub Actions workflow "CI / lint (pull_request)".
Analyze the workflow logs, identify the root cause of the failure, and implement a fix.
Job ID: 68962188992
Job URL: /primer/live-region-element/actions/runs/23670323424/job/68962188992?pr=356

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[changeset-bot]

⚠️ No Changeset found

Latest commit: 3212bf6

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[llastflowers]

@copilot Can you fix the formatting issue that is causing CI to fail here?

[Copilot]

@copilot Can you fix the formatting issue that is causing CI to fail here?

Fixed in 3212bf6 — reverted the accidental change to website/next-env.d.ts that was modifying it to include an import statement from a .next/ build artifact, which caused prettier to flag it.

[llastflowers]

@copilot can you review this PR again with consideration to the most recent commit?

[Copilot]

@copilot can you review this PR again with consideration to the most recent commit?

Here's a review of the PR with all commits included:

Changes:

1. packages/live-region-element/script/build — Replaces implicit .d.ts generation via rollup-plugin-typescript2 (which silently broke in v0.36.0 + TypeScript 5.9.3) with an explicit npx tsc invocation. Declarations go to dist/esm, then get copied/renamed to dist/cjs as .d.cts for CommonJS consumers.

2. packages/live-region-element/tsconfig.build.json — Adds "types": ["node"] to exclude the test-only vitest-dom/extend-expect type (from tsconfig.base.json) from production declaration outputs.

3. website/next-env.d.ts (commit 3212bf6) — Reverts an accidental Next.js build artifact that had been committed and was causing the prettier CI check to fail.

Local verification:

• npm run build → generates all expected .d.ts and .d.cts files ✅
• npm run lint:npm (publint --strict) → "All good!" ✅
• prettier --list-different → exits 0 (no issues) ✅

[llastflowers]

closing in favor of #366