feat(web): re-apply dashboard UI improvements on top of i18n

Re-applies changes from #9471 that were overwritten by the i18n PR:

- URL-based routing via react-router-dom (NavLink, Routes, BrowserRouter)
- Replace emoji icons with lucide-react in ConfigPage and SkillsPage
- Sidebar layout for ConfigPage, SkillsPage, and LogsPage
- Custom dropdown Select component (SelectOption) in CronPage
- Remove all non-functional rounded borders across the UI
- Fixed header with proper content offset

Made-with: Cursor

web/src/components/LanguageSwitcher.tsx

@@ -13,7 +13,7 @@ export function LanguageSwitcher() {
     <button
       type="button"
       onClick={toggle}
-      className="group relative inline-flex items-center gap-1.5 px-2 py-1 text-xs text-muted-foreground hover:text-foreground transition-colors cursor-pointer focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring rounded"
+      className="group relative inline-flex items-center gap-1.5 px-2 py-1 text-xs text-muted-foreground hover:text-foreground transition-colors cursor-pointer focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring"
       title={t.language.switchTo}
       aria-label={t.language.switchTo}
     >

web/src/components/ModelInfoCard.tsx

@@ -52,7 +52,7 @@ export function ModelInfoCard({ currentModel, refreshKey = 0 }: ModelInfoCardPro
   const hasCaps = caps && Object.keys(caps).length > 0;
 
   return (
-    <div className="rounded-lg border border-border/60 bg-muted/30 px-3 py-2.5 space-y-2">
+    <div className="border border-border/60 bg-muted/30 px-3 py-2.5 space-y-2">
       {/* Context window */}
       <div className="flex items-center gap-4 text-xs">
         <div className="flex items-center gap-1.5 text-muted-foreground">
@@ -90,22 +90,22 @@ export function ModelInfoCard({ currentModel, refreshKey = 0 }: ModelInfoCardPro
       {hasCaps && (
         <div className="flex flex-wrap items-center gap-1.5 pt-0.5">
           {caps.supports_tools && (
-            <span className="inline-flex items-center gap-1 rounded-full bg-emerald-500/10 px-2 py-0.5 text-[10px] font-medium text-emerald-600 dark:text-emerald-400">
+            <span className="inline-flex items-center gap-1 bg-emerald-500/10 px-2 py-0.5 text-[10px] font-medium text-emerald-600 dark:text-emerald-400">
               <Wrench className="h-2.5 w-2.5" /> Tools
             </span>
           )}
           {caps.supports_vision && (
-            <span className="inline-flex items-center gap-1 rounded-full bg-blue-500/10 px-2 py-0.5 text-[10px] font-medium text-blue-600 dark:text-blue-400">
+            <span className="inline-flex items-center gap-1 bg-blue-500/10 px-2 py-0.5 text-[10px] font-medium text-blue-600 dark:text-blue-400">
               <Eye className="h-2.5 w-2.5" /> Vision
             </span>
           )}
           {caps.supports_reasoning && (
-            <span className="inline-flex items-center gap-1 rounded-full bg-purple-500/10 px-2 py-0.5 text-[10px] font-medium text-purple-600 dark:text-purple-400">
+            <span className="inline-flex items-center gap-1 bg-purple-500/10 px-2 py-0.5 text-[10px] font-medium text-purple-600 dark:text-purple-400">
               <Brain className="h-2.5 w-2.5" /> Reasoning
             </span>
           )}
           {caps.model_family && (
-            <span className="inline-flex items-center gap-1 rounded-full bg-muted px-2 py-0.5 text-[10px] font-medium text-muted-foreground">
+            <span className="inline-flex items-center gap-1 bg-muted px-2 py-0.5 text-[10px] font-medium text-muted-foreground">
               {caps.model_family}
             </span>
           )}

web/src/components/OAuthProvidersCard.tsx

@@ -171,7 +171,7 @@ export function OAuthProvidersCard({ onError, onSuccess }: Props) {
                     {!p.status.logged_in && (
                       <span className="text-xs text-muted-foreground/80">
                         {t.oauth.notConnected.split("{command}")[0]}
-                        <code className="text-foreground bg-secondary/40 px-1 rounded">
+                        <code className="text-foreground bg-secondary/40 px-1">
                           {p.cli_command}
                         </code>
                         {t.oauth.notConnected.split("{command}")[1]}