Helpdock 0.5.1

A fix release for two admin defects that only show against a real api, so the
mock-backed test suites never caught them. No migration, configuration or API
change; upgrade by pulling the new image.

• Agent assist works in the production admin again. Since 0.4.0 the
  composer's Assist menu (suggest reply, summarize, suggest fields, translate,
  rewrite, draft article), the "items redacted before AI" notice, voice-note
  transcripts and Help center › Proposals called /api/api/…, got a 404 and
  stayed hidden. They now reach the api (#175).
• The "is viewing" indicator names colleagues for Agents. An Agent, who
  cannot read the staff list, saw part of a user id ("01a13522 is replying").
  Names now come from the department's assignable list, as the assignee picker's
  do (#175).

What's Changed

• fix: release workflow verifies the signer identity of the ref it ran under, and the manual mode finishes an unreleased tag by @Docker-Hunterpedia in #173
• fix: agent assist reaches the api in production builds; the collision indicator names colleagues for Agents by @Docker-Hunterpedia in #175
• docs: mark M10 Meta channels shipped by @Docker-Hunterpedia in #176
• docs: release notes for 0.5.1 by @Docker-Hunterpedia in #178
• chore: version packages by @github-actions[bot] in #177

Full Changelog: v0.5.0...v0.5.1