feat: Replace navigation logo with bold text wordmark

- Removed puma image from header navigation
- Replaced with bold 'pounce' text wordmark
- Uses Playfair Display font (font-display)
- Responsive sizing: 1.5rem (mobile) to 1.75rem (desktop)
- Clean, minimal, professional appearance
- Removed unused Image import dependency

frontend/src/components/Header.tsx

@@ -6,18 +6,13 @@ import { useStore } from '@/lib/store'
 import { LogOut, LayoutDashboard, Menu, X, Settings } from 'lucide-react'
 import { useState } from 'react'
 
-// Logo Component - Puma Image
+// Logo Component - Text Wordmark
 function Logo() {
   return (
     <div className="relative flex items-center">
-      <Image
-        src="/pounce-logo.png"
-        alt="pounce"
-        width={160}
-        height={80}
-        className="w-32 h-auto sm:w-40 sm:h-auto object-contain"
-        priority
-      />
+      <span className="font-display text-[1.5rem] sm:text-[1.75rem] font-bold tracking-tight text-foreground">
+        pounce
+      </span>
     </div>
   )
 }