refactor(scripts): resolve specifiers instead of pattern-matching one mistake

The first version banned `.js` specifiers by regex, which catches the bug that happened
and nothing adjacent to it. This runs the actual resolution algorithm with Turbopack's
rules — extensionAlias deliberately absent — and fails on anything that does not land on
a real file.

That covers the whole "Module not found" class rather than one shape of it: `.js`
specifiers, typo'd paths, files moved or deleted with a stale importer left behind, `@/`
aliases pointing nowhere, and `@sim/*` subpaths a package does not export. Verified
against three synthetic breakages the regex version passed clean:

    '@/lib/webhooks/providerz'  — '@/' alias matches a tsconfig path but nothing is there
    './does-not-exist'          — no file at that path
    '@sim/utils/chunking'       — @sim/utils does not export './chunking'

Getting to zero false positives on 37,307 specifiers needed three things the naive
version got wrong:

- tsconfig `paths` are per-workspace. `@/*` is `apps/sim/*` inside apps/sim but
  `apps/realtime/src/*` inside apps/realtime, and apps/sim maps `@sim/db/*` straight at
  the package directory, legitimately bypassing that package's exports map. One
  hardcoded alias produced ~30 false positives in apps/realtime alone.
- `exports` maps have wildcards. `@sim/emcn` publishes `"./*": "./src/*"`, so
  `@sim/emcn/components/code/code.css` is valid despite no literal entry.
- TSDoc contains example imports. `packages/db/triggers.ts` documents
  `import { ensureRowCountTriggers } from '@sim/db/triggers'` — a subpath the package
  deliberately does not export. Comments are now blanked in place, preserving byte
  offsets so reported line numbers stay exact.

Author: waleedlatif1