Meet streak calculation

[ShantKhatri]

Summary

Calculate the weekly-based meet streak from connection events.

Contexts

Weekly, not daily, since DevCard usage is event-driven. Self-shares must be excluded.

Tasks

• Weekly streak calculation logic (at least one new connection per week keeps it alive)
• Exclude self-shares (sharer scanning their own card)
• Handle streak freeze/reset when no events happen for weeks

Acceptance Criteria

• Streak increments and resets correctly against test scenarios
• Self-shares never count
• Tests added

Area

backend

Difficulty

Intermediate

[github-actions]

Hi @ShantKhatri,

Thanks for opening this issue.

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