Implement off-chain voting

[mesudip]

Outcome

Users can participate in verifiable off-chain voting based on the approved security and product design.

Scope

• Implement eligibility, ballot, tally, and result-verification flows
• Implement required privacy, audit, and abuse controls
• Integrate with profiles and proposal context
• Complete security review, accessibility validation, and operational testing

Acceptance criteria

• Scope is decomposed into independently deliverable child issues.
• Architecture and API decisions are linked from this issue.
• Test, documentation, observability, rollout, and failure behavior are defined where applicable.
• Epic exit criteria are verified before closure.

Planning note

This is a sample modernization epic. Its child features and tasks will be added after the board structure is reviewed.