Get Signed Url For Drawing

Generate a signed URL for a project/quote file path.

Used by the task integration panel preview, material-quote line attachments, and client PO links — same signing as the File Manager list endpoint.

All legacy logical buckets were consolidated into the jeevy-project-documents bucket with paths prefixed by the old bucket name (see scripts/migrate_to_project_documents.py). Callers may pass either the legacy logical bucket + unprefixed path, or jeevy-project-documents + an already-prefixed path — both resolve to the same object.

Signing is refused when the object is missing (HTTP 404) so the viewer cannot be handed a URL that dumps S3's NoSuchKey XML. When the caller guessed the commercial project bucket and the bytes live in the export-controlled twin (same key), that sibling is tried before 404.