wasm/example: use bun; stop tracking package-lock.json + tsbuildinfo
- Switch the example to bun (bun install / bun run dev); pre-hooks call
node scripts/copy-wasm.mjs directly so they're package-manager-agnostic.
- Untrack the accidentally-committed package-lock.json and
tsconfig.tsbuildinfo, and gitignore lockfiles + *.tsbuildinfo.
- Console (wasm:example) and docs updated to bun.
Verified: `bun run build` succeeds.