fetch-urls.ts called sharp(buffer).webp() directly on the raw, undecoded buffer for CLI-decoded formats (HEIC, RAW, PSD, ...), which throws and gets silently swallowed, so URL-imported files in those formats came back with no preview and 0x0 dimensions. Decodes once before both preview generation and dimension lookup, mirroring the pattern already used elsewhere in the codebase.
Fixes#634
Coverage 83.6 to 87.36% lines, 81.63 to 84.14% branches. Mutation testing across five packages: image-engine 85, media-engine 92, doc-engine 87, shared+enterprise 86, apps/api security and jobs slice. Runs all five lanes weekly. Fixes the silently-broken mutation CI (babel pin), a redact-pdf envelope-shape test bug, an untested enterprise license valid-signature path, and an audit test that only exercised a hand-copied reproduction. Test and config only, no product code changes beyond the babel pin and one test-only oidc export. Full suite: 16,712 pass, 0 fail.