fix: set terminal default to 8px and minimum to 4px

- Reduce MIN_FONT_SIZE from 8 to 4 for maximum text size reduction
- Set default font size to 8px for both mobile and desktop
- Allows very small terminal text for mobile viewport optimization

Quality gates: TypeScript check passed, production build successful

apps/web/src/components/terminal.tsx

@@ -21,7 +21,7 @@ interface TerminalProps {
 }
 
 const FONT_SIZE_KEY = "terminal-font-size";
-const MIN_FONT_SIZE = 8;
+const MIN_FONT_SIZE = 4;
 const MAX_FONT_SIZE = 24;
 const RECONNECT_ATTEMPTS = 3;
 const RECONNECT_DELAY_BASE = 1000;
@@ -51,13 +51,13 @@ export const TerminalComponent: React.FC<TerminalProps> = ({
   const activeModifierRef = useRef(activeModifier);
   activeModifierRef.current = activeModifier;
   const [fontSize, setFontSize] = useState(() => {
-    if (typeof window === "undefined") return isMobile ? 10 : 10;
+    if (typeof window === "undefined") return isMobile ? 8 : 8;
     const stored = localStorage.getItem(FONT_SIZE_KEY);
     if (stored) {
       const parsed = parseInt(stored, 10);
       return Math.max(MIN_FONT_SIZE, Math.min(MAX_FONT_SIZE, parsed));
     }
-    return isMobile ? 10 : 10;
+    return isMobile ? 8 : 8;
   });
   const lastPingRef = useRef<number>(0);
   const heartbeatCheckRef = useRef<number | null>(null);