fix(parser): point the published worker URL at the file the package ships

Problem

• dist/worker-parser.js carried new URL('./parser.worker.ts', import.meta.url) verbatim from source, while the tarball ships only dist/parser.worker.js.
• new WorkerParser() rejected through worker.onerror for every npm consumer, and a bundler that resolves the literal at build time failed outright.

$ curl -s https://cdn.jsdelivr.net/npm/@ifc-lite/parser@7.0.0/dist/worker-parser.js | grep -n "parser.worker.ts"
57:   : new Worker(new URL('./parser.worker.ts', import.meta.url), { type: 'module' });

$ curl -s -o /dev/null -w "%{http_code}\n" .../dist/parser.worker.ts
404
$ curl -s -o /dev/null -w "%{http_code}\n" .../dist/parser.worker.js
200

Change

• The build rewrites the emitted specifiers to the .js file tsc produced.
• A second step re-derives from the emitted files alone whether every new URL('./…', import.meta.url) resolves to something dist holds, and fails the build when one does not.

Two steps, because the second is the half that was missing

• @ifc-lite/geometry has rewritten its worker URLs since #633 and shipped the same defect again in #637, when the rewrite named the dist files to touch and missed one.
• Nothing looked at the output, and a rewrite that quietly does nothing produces the same green build as one that works.
• Neither step here carries a list of files. The rewrite walks all 120 emitted files and touches only a specifier whose .js sibling tsc actually emitted; one without a sibling is left in place and reported, since rewriting it would swap one missing file for another and hide it from the verifier.

$ pnpm exec tsc && node ./scripts/verify-dist-worker-urls.mjs
verify-dist-worker-urls: 1 specifier(s) point at a file this package does not ship:
  dist/worker-parser.js: ./parser.worker.ts
-> exit 1

$ pnpm --filter @ifc-lite/parser build
rewrite-worker-urls: scanned 120 emitted file(s), rewrote 1.
  worker-parser.js: ./parser.worker.ts -> ./parser.worker.js
verify-dist-worker-urls: 1 URL specifier(s) in 120 emitted file(s) all resolve.

Deliberately not in this diff