feat: add subtle recency status dot to repository cards (#2568)

[Anuj-verse]

Closes #2568

Adds a small, non-intrusive colored dot visual indicator next to each repository card to help users quickly identify recently active projects while scanning the list — as proposed in the issue.

Indicator logic (based on existing relative "last activity" string):

• Green (emerald-400): very recent (< ~48h) — matches hours/minutes/seconds or "a day ago"
• Amber (amber-500): recent (2–7 days ago) —
• Gray (zinc-800): older (>7 days)

Implementation details:

• Pure UI change in the frontend (Vue component) — no backend, no new data fetching, no sorting/filtering changes
• Uses simple computed property + Tailwind classes only
• Dot is small (w-4 h-4), has subtle ring for visibility, includes title attribute for hover info + accessibility
• Placed right after the repo name link (easy to adjust if preferred)
• Always shown (gray for older repos) to keep layout consistent, but very subtle when inactive

Screenshots

[vercel]

@Anuj-verse is attempting to deploy a commit to the DeepSource Team on Vercel.

A member of the Team first needs to authorize it.