Remove Debug tab completely

- Remove debug screen from tab navigator
- Delete app/(tabs)/debug.tsx file

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

app/(tabs)/_layout.tsx

@@ -72,13 +72,6 @@ export default function TabLayout() {
           ),
         }}
       />
-      {/* Debug tab - HIDDEN, no longer needed */}
-      <Tabs.Screen
-        name="debug"
-        options={{
-          href: null,
-        }}
-      />
       {/* Hide explore tab */}
       <Tabs.Screen
         name="explore"