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/skills/SkillsPage.tsx

@@ -193,7 +193,7 @@ export const SkillsPage = forwardRef<SkillsPageHandle, SkillsPageProps>(
     }, [skills, searchQuery, filterStatus]);
 
     return (
-      <div className="mx-auto max-w-[56rem] px-6 flex flex-col h-[calc(100vh-8rem)] overflow-hidden bg-background/50">
+      <div className="px-6 flex flex-col h-[calc(100vh-8rem)] overflow-hidden bg-background/50">
         {/* 技能网格（可滚动详情区域） */}
         <div className="flex-1 overflow-y-auto overflow-x-hidden animate-fade-in">
           <div className="py-4">

src/components/skills/UnifiedSkillsPanel.tsx

@@ -133,7 +133,7 @@ const UnifiedSkillsPanel = React.forwardRef<
   }));
 
   return (
-    <div className="mx-auto max-w-[56rem] px-6 flex flex-col h-[calc(100vh-8rem)] overflow-hidden">
+    <div className="px-6 flex flex-col h-[calc(100vh-8rem)] overflow-hidden">
       {/* Info Section */}
       <div className="flex-shrink-0 py-4 glass rounded-xl border border-white/10 mb-4 px-6">
         <div className="text-sm text-muted-foreground">