Make getTranscripts cross-platform (remove Unix find dependency)

[jkarthid]

What & why

npm run format is currently broken on Windows. scripts/format.js discovered transcripts by shelling out to a Unix file finder:

const { stdout } = await exec('find **/*.md')

On Windows, find is a text-search utility (not a file finder), so it fails immediately:

FIND: Parameter format not correct

It also implicitly depended on sh glob semantics (where ** collapses to *, matching only */*.md — one directory deep), which is fragile and shell-dependent.

Changes

• Replace the find subprocess with a pure-Node fs.readdir walk in getTranscripts(). It reads each top-level podcast directory and collects its .md files, skipping hidden / node_modules / scripts folders.
• Drop the now-unused util + child_process imports; add path.
• Fill in the previously empty getTranscripts test (it had a // TODO and zero assertions) with checks that it returns a non-empty list of one-level-deep .md paths.

Behavior

Faithful to the original "one directory deep" matching, so root files like README.md are still never touched. Verified locally: getTranscripts() returns 2005 transcripts, all .md, none at the repo root.

Testing

npm run format:test → 15/15 tests pass (including the new assertions). The fix makes npm run format runnable on Windows, macOS, and Linux without relying on any external command.