refactor: improve proxy group UI and spacing (#2835)

- Increased spacing in proxy-groups.tsx by adjusting the right position
  of the alphabet selector to provide better visual separation
- Enhanced spacing in proxy-render.tsx with larger margins and padding
  - Increased group item margins from 8px to 10px with 16px horizontal spacing
  - Expanded border radius from 8px to 10px for smoother appearance
  - Improved ProxyHead component spacing with pl: 3, pr: 3.5
  - Enhanced grid spacing in proxy collection items from 1 to 1.5
  - Adjusted padding for better visual hierarchy

These changes create a more polished, spacious layout with improved
readability and touch targets.

src/components/proxy/proxy-groups.tsx

@@ -508,8 +508,13 @@ export const ProxyGroups = (props: Props) => {
         )}
       />
       <ScrollTopButton show={showScrollTop} onClick={scrollToTop} />
-
-      <AlphabetSelector ref={alphabetSelectorRef} style={{ maxHeight }}>
+      <AlphabetSelector
+        ref={alphabetSelectorRef}
+        style={{
+          maxHeight,
+          right: 10,
+        }}
+      >
         <div className="scroll-container">
           <div ref={letterContainerRef} className="letter-container">
             {groupFirstLetters.map((name) => (