The store-URL support extracted the app ID into a local but never wrote
it back, so steamScraper still received the full URL, keyed the Steam API
response by the URL string, threw, and its caught Error object flowed into
Game.create() — surfacing as misleading 'Path lastModifiedBy / createdBy /
frontImage / title is required' validation errors.
- add utils/normalizeSteamId: digits pass through, /app/<id>/ (plus
/agecheck/app/<id>/ and query strings) extracts the ID, empty -> '',
anything else -> null (no .match()[0] / .includes crash on bad input)
- create(): 400 cleanly on unrecognized input, write the normalized ID
back to req.body.steamId so dup checks, scraper, and stored doc agree
- guard the scrape result (missing title/frontImage, false, or Error) and
400 'Steam lookup failed' instead of leaking it into Game.create
