test: make V2 smoke test copy-out-and-run (.mjs, plain node)

[tian-lan-landing]

Follow-up to #72. The V2 smoke test was a .ts runnable only via the repo's yarn tsn (ts-node). A QA person who just npm install github:landing-ai/ade-typescript#...'d the package into their own project couldn't run it without adding a TypeScript toolchain (ts-node/tsx + tsconfig).

This converts examples/v2_smoke_test.ts → examples/v2_smoke_test.mjs (plain ESM JavaScript), so it mirrors ade-python's examples/v2_smoke_test.py: install the package, drop the file into any project, and node v2_smoke_test.mjs — no TS toolchain, no repo checkout.

• Runtime logic is unchanged (only type annotations stripped); it uses the same import LandingAIADE from 'landingai-ade' default-import pattern the built package already ships for V1 users.
• Type safety is still covered by the SDK's tsc (CI), the jest suite, and the shipped .d.ts.
• The .ts version (identical logic) passed 7/7 live against api.ade.staging in feat: V2 parse & extract SDK support (client.v2) #72.

🤖 Generated with Claude Code

[tian-lan-landing]

Consumer-install validation ✅

Simulated a real consumer in a fresh project (not the repo checkout):

1. npm install github:landing-ai/ade-typescript#chore/v2-smoke-test-mjs → resolved from git (…#3defc30) and built via the package's prepare step (npm ls shows the git URL, not a local/link install).
2. Copied examples/v2_smoke_test.mjs into the project and ran it with plain node (no ts-node/tsx):

node v2_smoke_test.mjs --only files,extract
V2 base: https://api.ade.staging.landing.ai
  PASS  files.upload   → file_ref=storage-ref:…
  PASS  v2.extract      → {"company":"Acme Inc.","revenue":"$1,250,000"}  version=extract-20260630
0 failed / 2 run   (exit 0)

Real staging round-trips — confirms the copy-out-and-run flow works with plain node, matching ade-python's example.

Note: the built entrypoint installs at the package root (node_modules/landingai-ade/index.mjs) per the flat git-swap publish layout; import LandingAIADE from 'landingai-ade' resolves via exports, so consumers are unaffected.

🤖 Generated with Claude Code