feat: constrain section content width with max-w-section

Adds max-w-section (56rem via --container-section token) to the
experience, projects, and skills section wrappers for consistent
readable line length across all content areas.

src/widgets/ExperienceSection/ui/ExperienceSection/ExperienceSection.tsx

@@ -13,7 +13,7 @@ export default async function ExperienceSection() {
   });
 
   return (
-    <div className="space-y-6">
+    <div className="space-y-6 max-w-section">
       {items.map((exp) => (
         <ExperienceCard
           key={exp.id}

src/widgets/ProjectsSection/ui/ProjectsSection/ProjectsSection.tsx

@@ -25,7 +25,7 @@ export default async function ProjectsSection() {
   });
 
   return (
-    <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
+    <div className="grid grid-cols-1 md:grid-cols-2 gap-6 max-w-section">
       {items.map((project) => (
         <ProjectCard
           key={project.id}

src/widgets/SkillsSection/ui/SkillsSection/SkillsSection.tsx

@@ -20,7 +20,7 @@ export default async function SkillsSection() {
   const categories = groupByKey(data.items, 'category');
 
   return (
-    <div className="space-y-12">
+    <div className="space-y-12 max-w-section">
       {Object.entries(categories).map(([category, items]) => (
         <div key={category} className="space-y-4">
           <h3 className="text-xl font-bold uppercase tracking-widest opacity-50">{category}</h3>