mesh.slug actually carries a UNIQUE constraint (mesh_slug_unique)
even though the schema comment claimed otherwise. Trying to rename
to a slug another mesh already owns blew up as a generic 500.
Now: caught at the route, surfaced as 409 with body
{"error":"slug \"<x>\" is already taken"}; CLI maps it to
EXIT.ALREADY_EXISTS and prints the message.
Schema comment corrected to match DB reality.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
65e63b0b27