Fix/prmetrics empty state

[mrunalC27]

Summary

Adds a proper empty state to the PR Analytics section when a user has no pull requests instead of showing empty metrics and charts.

Closes #215

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor / code cleanup

Changes Made

• Added a zero-state check using metrics?.total === 0
• Added a user-friendly empty state message for users with no PRs
• Used var(--muted-foreground) styling to match existing UI patterns
• Updated the PRData interface to include the total field

How to Test

Steps for the reviewer to verify this works:

1. Run the application locally
2. Open the PR Analytics section with an account that has no pull requests
3. Verify that the empty state message appears instead of empty charts/cards
4. Verify that accounts with PR data still display analytics correctly

Screenshots (if UI change)

Added empty state UI for users with no pull requests.

Checklist

• Linked issue in summary
• npm run lint passes locally
• No TypeScript errors (npm run type-check)
• Self-reviewed the diff
• Added/updated tests if applicable

[vercel]

@mrunalC27 is attempting to deploy a commit to the PRIYANSHU DOSHI's projects Team on Vercel.

A member of the Team first needs to authorize it.

[Priyanshu-byte-coder]

Two issues:

1. This PR includes #325's DashboardHeader.tsx changes
The DashboardHeader changes are already being reviewed in #325. Once #325 merges, rebase this PR on main so only the PRMetrics empty-state diff remains. Don't merge this before #325 merges (or it would land both sets of changes at once, making the history harder to read).

2. Indentation inconsistency in the empty-state ternary

      ) : (
-       <div className="grid ...
// becomes
        ) : metrics?.total === 0 ? (
          <div className="flex ...

The ) : moved from 6-space to 8-space indent and the content from 8 to 10. Match the surrounding ternary branches' indentation.

[mrunalC27]

fixed it

[Priyanshu-byte-coder]

1. total field not returned by the API — the component checks metrics?.total === 0 but /api/metrics/prs doesn't return a total field. The empty state will never render because metrics.total will be undefined, not 0. Update the API route to return total as well.

2. JSX indentation is malformed — the new ternary branch and the <div className="grid"> inside it are indented inconsistently (mixed 10-space and 12-space). Fix to match the surrounding 8-space indent — or run Prettier.