Move theme toggle to account actions

[Romonaga]

Change Type

• Feature
• Bug fix
• Refactor
• Documentation / workflow artifact
• Repo organization / cleanup
• Other: ___

Linked Workstream Change

• Linked Verlyn change: circuit-shelf-12
• No change applies - reason: ___

Verlyn PR Metadata

Verlyn PR creator: ___

Acceptance Criteria

• Theme control appears with Account, Monitor, and Sign out on desktop and mobile; workspace topbar no longer carries the theme toggle; clicking the control switches light/dark themes without console errors.

Verification Runs Completed

• Session baseline
• Architecture check (if configured)
• Workstream validation: python scripts/repo_helpers/workflow/validate.py <id> --strict
• Other:
  • ___

Coverage Summary

• 4 of 4 tracked work items are complete.

AI Assistance Disclosure

• AI-assisted - tool(s) used: Codex
• Human-authored only

Accountable human owner: hellweek

Seeded by Verlyn for Move theme toggle to account actions: this tracked change is being managed through Verlyn's solo workflow path. Replace this note with the concrete AI-assisted tools and scope before merge if implementation, review, or packet authoring used AI, or replace it with 'Human-authored only.' when no AI assistance materially shaped the final change.

Independent Cross-Agent Review

• Not required for this change - reason: ___
• Completed - reviewer tool: Verlyn workflow gate | findings summary: No blocking findings recorded.
  • Unresolved findings:
    • ___

Rollback Plan

• Revert the bugfix for Move theme toggle to account actions if the targeted regression returns or new regressions appear.

Handoff Status

• All acceptance criteria satisfied
• DB-backed work items updated
• Outstanding blockers or deferred items noted
• Ready to merge