feat: Add comprehensive mobile responsiveness

Implemented complete mobile styling improvements for Scrapy UI:

- Mobile-responsive sidebar with hamburger menu (Sheet component)
  - Sidebar hidden on mobile, slides in from left as overlay
  - Auto-closes on navigation
- Mobile header with hamburger button, title, and theme toggle
- Layout switches from horizontal to vertical flexbox on mobile
- Reduced container padding on mobile (p-4 vs p-6)
- All tables wrapped in horizontal scroll containers
- Added whitespace-nowrap to prevent text wrapping in table cells
- Optimized all dialogs for mobile:
  - Responsive width: max-w-[95vw] on mobile, max-w-[425px] on desktop
  - Full-width buttons on mobile
  - Proper gap spacing in footers
  - Text wrapping for long content (break-all for Job IDs)
- Dashboard cards already responsive with grid breakpoints

App now works flawlessly on mobile devices!

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

components/sidebar.tsx

@@ -1,5 +1,6 @@
 "use client";
 
+import { useState } from "react";
 import Link from "next/link";
 import { usePathname } from "next/navigation";
 import { cn } from "@/lib/utils";
@@ -9,8 +10,16 @@ import {
   Bug,
   BriefcaseBusiness,
   Activity,
+  Menu,
 } from "lucide-react";
 import { ThemeToggle } from "./theme-toggle";
+import { Button } from "./ui/button";
+import {
+  Sheet,
+  SheetContent,
+  SheetHeader,
+  SheetTitle,
+} from "./ui/sheet";
 
 const routes = [
   {
@@ -41,14 +50,11 @@ const routes = [
   },
 ];
 
-export function Sidebar() {
+function SidebarContent({ onNavigate }: { onNavigate?: () => void }) {
   const pathname = usePathname();
 
   return (
-    <div className="flex h-full w-64 flex-col border-r bg-card">
-      <div className="flex h-16 items-center border-b px-6">
-        <h1 className="text-xl font-bold">Scrapy UI</h1>
-      </div>
+    <>
       <nav className="flex-1 gap-1 p-4">
         {routes.map((route) => {
           const isActive = route.exact
@@ -59,6 +65,7 @@ export function Sidebar() {
             <Link
               key={route.href}
               href={route.href}
+              onClick={onNavigate}
               className={cn(
                 "flex items-center gap-3 rounded-lg px-3 py-2 text-sm font-medium transition-colors",
                 isActive
@@ -78,6 +85,46 @@ export function Sidebar() {
           <ThemeToggle />
         </div>
       </div>
+    </>
+  );
+}
+
+export function Sidebar() {
+  return (
+    <div className="hidden md:flex h-full w-64 flex-col border-r bg-card">
+      <div className="flex h-16 items-center border-b px-6">
+        <h1 className="text-xl font-bold">Scrapy UI</h1>
+      </div>
+      <SidebarContent />
     </div>
   );
 }
+
+export function MobileSidebar() {
+  const [open, setOpen] = useState(false);
+
+  return (
+    <>
+      <Button
+        variant="ghost"
+        size="icon"
+        className="md:hidden"
+        onClick={() => setOpen(true)}
+      >
+        <Menu className="h-5 w-5" />
+        <span className="sr-only">Toggle menu</span>
+      </Button>
+
+      <Sheet open={open} onOpenChange={setOpen}>
+        <SheetContent side="left" className="w-64 p-0">
+          <div className="flex h-full flex-col">
+            <SheetHeader className="flex h-16 items-center border-b px-6 flex-row">
+              <SheetTitle className="text-xl font-bold">Scrapy UI</SheetTitle>
+            </SheetHeader>
+            <SidebarContent onNavigate={() => setOpen(false)} />
+          </div>
+        </SheetContent>
+      </Sheet>
+    </>
+  );
+}