test: split package smoke verification

[samlaycock]

Summary

• Move the expensive install/build/pack/install package smoke path into bun run test:package.
• Keep fast package metadata and export-shape checks in the default bun test suite.
• Run bun run test:package explicitly in CI and document the command in package export docs.
• Add a patch changeset for the test workflow/script change.

Closes #56

Verification

• bun fmt
• bun lint:fix
• bun test
• bun run test:package
• bun typecheck

[greptile-apps]

Greptile Summary

This PR splits the expensive end-to-end package smoke test (install → build → pack → consumer-install → ESM/CJS execution) into a dedicated test:package script, leaving only fast package-metadata and export-shape assertions in the default bun test suite. CI is updated to run both steps sequentially, and the docs/package-exports.md page is extended with a Verification section documenting both commands.

• test/package-smoke.ts contains the extracted integration test with the timeout corrected to 60_000 ms; test/package.test.ts retains lightweight package.json structure assertions.
• package.json gains a test:package script that explicitly targets the smoke file, preventing it from being picked up by the default test glob.
• A patch-level changeset is included as required by project convention.

Confidence Score: 5/5

Safe to merge — this is a pure test-infrastructure reorganisation with no changes to production code or package exports.

All production code is untouched. The smoke test logic is identical to what was in package.test.ts; the only meaningful change is the 15s to 60s timeout correction and the file split. CI covers both test paths. No regressions are expected.

No files require special attention.

Important Files Changed

Filename	Overview
test/package-smoke.ts	New smoke test file extracted from package.test.ts; timeout corrected to 60s; structure and logic unchanged from prior code
test/package.test.ts	Heavy install/build/pack smoke test removed; replaced with fast package.json metadata and exports-shape assertions that are safe to run in the default suite
.github/workflows/test.yml	Added a dedicated CI step that runs bun run test:package after the existing bun test step
package.json	Added test:package script that explicitly targets the smoke test file via bun test ./test/package-smoke.ts
docs/package-exports.md	Added a Verification section documenting the two-tier test commands
.changeset/quiet-maps-begin.md	Patch-level changeset added as required by project convention

_{Reviews (2): Last reviewed commit: "test: relax package smoke timeout" | Re-trigger Greptile}