fix(ui): resolve Select dropdown not appearing in FullScreenPanel

- Increase SelectContent z-index from z-50 to z-[100] to appear above FullScreenPanel (z-[60])
- Replace form.watch() with form.getValues() in useCallback handlers for correct react-hook-form usage
- Remove max-w-[56rem] constraints from various panels for consistent full-width layout

src/components/common/FullScreenPanel.tsx

@@ -72,7 +72,7 @@ export const FullScreenPanel: React.FC<FullScreenPanelProps> = ({
             }
           >
             <div
-              className="mx-auto max-w-[56rem] px-6 w-full flex items-center gap-4"
+              className="px-6 w-full flex items-center gap-4"
               data-tauri-drag-region
               style={{ WebkitAppRegion: "drag" } as React.CSSProperties}
             >
@@ -94,7 +94,7 @@ export const FullScreenPanel: React.FC<FullScreenPanelProps> = ({
 
           {/* Content */}
           <div className="flex-1 overflow-y-auto scroll-overlay">
-            <div className="mx-auto max-w-[56rem] px-6 py-6 space-y-6 w-full">
+            <div className="px-6 py-6 space-y-6 w-full">
               {children}
             </div>
           </div>
@@ -105,7 +105,7 @@ export const FullScreenPanel: React.FC<FullScreenPanelProps> = ({
               className="flex-shrink-0 py-4 border-t border-border-default"
               style={{ backgroundColor: "hsl(var(--background))" }}
             >
-              <div className="mx-auto max-w-[56rem] px-6 flex items-center justify-end gap-3">
+              <div className="px-6 flex items-center justify-end gap-3">
                 {footer}
               </div>
             </div>