V166: frozen comment attribution — who a comment is FROM, at the time.

Two problems, one row.

The name has to be frozen

A comment header used to render user.email, which on a public issue board published a full address next to every remark. Replacing it with a live name chain fixes the address but not the deeper issue: a name resolved at RENDER time rewrites history. Someone leaves, is renamed, or finally fills in their profile, and every comment they ever wrote is silently re-signed. author_display_name records what the world was shown when the comment was made.

Null for every existing row, on purpose: a backfill would invent a history we do not have, so old rows keep resolving live and only new ones are pinned.

Speaking for the project

Someone answering on their employer's public board may be speaking as themselves or on behalf of the project, and those are different acts. The choice is stored, not recomputed: recomputing means a membership change retroactively alters who said what — and worse, un-masks somebody who deliberately posted under the project's name.

user_uuid is never cleared. Posting as the project changes what the PUBLIC sees, and nothing else: internally the actual author stays on the row, so moderation, audit and "who actually said this" keep working. A shared voice with no accountable person behind it is how this feature goes wrong.

attributed_label is frozen alongside attributed_project_uuid for the same reason prices are snapshotted on orders: the project may be renamed or deleted, and the comment should still say what it said.

No FK on attributed_project_uuid — projects live in an optional package, exactly like the mention targets in V165.