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/pages/AnalyticsPage.tsx

@@ -74,11 +74,11 @@ function TokenBarChart({ daily }: { daily: AnalyticsDailyEntry[] }) {
         </div>
           <div className="flex items-center gap-4 text-xs text-muted-foreground">
           <div className="flex items-center gap-1.5">
-            <div className="h-2.5 w-2.5 rounded-sm bg-[#ffe6cb]" />
+            <div className="h-2.5 w-2.5 bg-[#ffe6cb]" />
             {t.analytics.input}
           </div>
           <div className="flex items-center gap-1.5">
-            <div className="h-2.5 w-2.5 rounded-sm bg-emerald-500" />
+            <div className="h-2.5 w-2.5 bg-emerald-500" />
             {t.analytics.output}
           </div>
         </div>
@@ -97,7 +97,7 @@ function TokenBarChart({ daily }: { daily: AnalyticsDailyEntry[] }) {
               >
                 {/* Tooltip */}
                 <div className="absolute bottom-full left-1/2 -translate-x-1/2 mb-2 hidden group-hover:block z-10 pointer-events-none">
-                  <div className="rounded-md bg-card border border-border px-2.5 py-1.5 text-[10px] text-foreground shadow-lg whitespace-nowrap">
+                  <div className="bg-card border border-border px-2.5 py-1.5 text-[10px] text-foreground shadow-lg whitespace-nowrap">
                     <div className="font-medium">{formatDate(d.day)}</div>
                     <div>{t.analytics.input}: {formatTokens(d.input_tokens)}</div>
                     <div>{t.analytics.output}: {formatTokens(d.output_tokens)}</div>