W167: Get document detail

Detail row plus a short-lived signed download URL — the download path. Triggered when the user clicks a document row to open/download it.

Steps

1. Load + sign. Call Documents.getByIdWithSignedUrl(documentId, 900) — reads the row, then mints a V4 read-signed URL for gcsPath with a 15-minute TTL.

Returns

The Document row extended with signedUrl.

Business rules

• The row stores gcsPath, never a URL; every download link is minted per request and goes stale after 15 minutes.
• Under STORAGE_EMULATOR_HOST (local dev) the URL is a plain emulator media URL — fake-gcs-server can't verify signatures.

Errors

Condition	Error
Document not found in this org	not_found