refactor: unify focus styles across all input fields

Replace inconsistent focus border styles with a unified soft blue ring effect
across all input and textarea components.

Changes:
- Add consistent focus:ring styles to Input and Textarea components
- Use focus:ring-blue-500/20 (light) and focus:ring-blue-400/20 (dark)
- Remove focus border color changes for a more subtle design
- Update ApiKeyInput to match the unified focus style
- Update all manual textarea elements (Codex and Claude configs)

Benefits:
- Consistent visual feedback across all form inputs
- Soft, elegant focus indication with blue glow effect
- No jarring border color changes
- Better user experience with subtle, professional styling

The focus effect now uses only a soft blue ring (20% opacity) without
changing border colors, creating a more refined and less distracting
interaction pattern.

src/components/providers/forms/CodexConfigSections.tsx

@@ -36,7 +36,7 @@ export const CodexAuthSection: React.FC<CodexAuthSectionProps> = ({
         placeholder={t("codexConfig.authJsonPlaceholder")}
         rows={6}
         required
-        className="w-full px-3 py-2 border border-border-default  dark:bg-gray-800 dark:text-gray-100 rounded-lg text-sm font-mono focus:outline-none focus:ring-2 focus:ring-blue-500/20 dark:focus:ring-blue-400/20 focus:border-border-active  transition-colors resize-y min-h-[8rem]"
+        className="w-full px-3 py-2 border border-border-default  dark:bg-gray-800 dark:text-gray-100 rounded-lg text-sm font-mono focus:outline-none focus:ring-2 focus:ring-blue-500/20 dark:focus:ring-blue-400/20  transition-colors resize-y min-h-[8rem]"
         autoComplete="off"
         autoCorrect="off"
         autoCapitalize="none"
@@ -126,7 +126,7 @@ export const CodexConfigSection: React.FC<CodexConfigSectionProps> = ({
         onChange={(e) => onChange(e.target.value)}
         placeholder=""
         rows={8}
-        className="w-full px-3 py-2 border border-border-default  dark:bg-gray-800 dark:text-gray-100 rounded-lg text-sm font-mono focus:outline-none focus:ring-2 focus:ring-blue-500/20 dark:focus:ring-blue-400/20 focus:border-border-active  transition-colors resize-y min-h-[10rem]"
+        className="w-full px-3 py-2 border border-border-default  dark:bg-gray-800 dark:text-gray-100 rounded-lg text-sm font-mono focus:outline-none focus:ring-2 focus:ring-blue-500/20 dark:focus:ring-blue-400/20  transition-colors resize-y min-h-[10rem]"
         autoComplete="off"
         autoCorrect="off"
         autoCapitalize="none"