getsentry/symbolic: wasm smoke test pattern — smoke-test.mjs + build-npm.sh + ci.yml wasm-smoke job

symbolic-wasm smoke test pattern: Two-file approach in symbolic-wasm/npm/: smoke-test.mjs (orchestrator: packs tgz, installs to temp dir, resolves wasm via exports map, spawns node --test on package-smoke.test.mjs) + package-smoke.test.mjs (node:test assertions against installed package via initSync). Test files excluded from files[] in package.json — nothing extra ships to consumers. Wired into build-npm.sh replacing bare npm pack. CI: wasm-smoke job in ci.yml. cd symbolic-wasm/npm && npm test runs the suite. Pack+install approach catches exports-map/resolution breakage, not just runtime errors. CRITICAL: wasm-pack test --node does NOT exercise the shipped artifact — it compiles tests with its own generated glue, never loads --target web symbolic.js + symbolic_bg.wasm via initSync. Confirmed by Burak Yigit Kaya: 'wasm-pack test sails past it because it builds its own glue and never loads what we ship'. PR #993 adds smoke tests.