Fix nav bar alignment — mobile boxes misaligned + desktop rounded vs square inconsistency

[realproject7]

Two nav bar styling bugs

1. Mobile: boxes not aligned (Image 207)

The PFP/username box on the left is slightly higher than the hamburger box on the right. They must be perfectly vertically aligned — same height, same vertical position.

Fix: ensure both boxes use identical padding, border, and are wrapped in a flex container with `items-center`.

2. Desktop: rounded pill vs mobile square border inconsistency (Image 208)

Desktop nav uses `rounded-full` (pill shape) for the wallet button, but mobile uses `rounded` (square with slight radius). Pick one consistent style — recommend square/rounded for both to match PlotLink's terminal aesthetic (not rounded-full pill).

Files to modify

• `src/components/ConnectWallet.tsx` — consistent border-radius
• `src/components/NavBar.tsx` — fix mobile flex alignment

Branch

`task/692-nav-alignment`

Self-Verification (T3)

• Mobile: both boxes perfectly vertically aligned (same height + position)
• Desktop + mobile: same border-radius style (both square/rounded, not mixed)
• `npm run build` passes