feat: comprehensive responsive design implementation for mobile devices

This commit implements a complete responsive design overhaul making the Supervisor UI fully mobile-friendly and beautiful across all devices (320px phones to 4K displays).

## Phase 1: Mobile Navigation
- Add hamburger menu to Navbar with slide-out drawer
- Auto-close on navigation with body scroll lock
- Responsive logo sizing

## Phase 2: Touch-Friendly Buttons
- Increase touch targets to 44px on mobile (36px for small buttons)
- Add responsive button layouts in ProcessCard
- Flex-wrap prevents cramped button rows

## Phase 3: Responsive Spacing & Typography
- Add responsive padding to Card components (p-4 md:p-6)
- Scale typography across breakpoints (text-xl md:text-2xl)
- Responsive spacing in AppLayout and all pages

## Phase 4: Mobile-Friendly Tables
- Dual layout for ConfigTable: table on desktop, cards on mobile
- Preserve all data with proper formatting and wrapping
- Hide table on mobile, show card-based layout

## Phase 5: Modal Improvements
- Add horizontal padding (p-4) to all modals
- Prevent edge-touching on mobile devices
- Fixed SignalSender, KeyboardShortcutsHelp, StdinInput modals

## Phase 6: Page-Specific Layouts
- Processes page: responsive header, controls, and grid spacing
- BatchActions bar: full-width on mobile, centered on desktop
- Logs page: responsive controls and height calculations
- Config page: responsive header and error states

## Phase 7: Polish & Final Touches
- Add viewport meta tag to layout
- Responsive empty states and loading skeletons
- Consistent responsive sizing across all error messages
- Mobile-first typography scaling

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

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

app/config/page.tsx

@@ -12,13 +12,13 @@ export default function ConfigPage() {
 
   if (isError) {
     return (
-      <div className="space-y-6">
-        <h1 className="text-3xl font-bold">Configuration</h1>
+      <div className="space-y-4 md:space-y-6">
+        <h1 className="text-2xl sm:text-3xl font-bold">Configuration</h1>
         <Card className="border-destructive/50">
-          <CardContent className="p-12 text-center">
-            <AlertCircle className="h-12 w-12 text-destructive mx-auto mb-4" />
-            <h2 className="text-xl font-semibold mb-2">Failed to load configuration</h2>
-            <p className="text-muted-foreground">
+          <CardContent className="p-8 md:p-12 text-center">
+            <AlertCircle className="h-10 w-10 md:h-12 md:w-12 text-destructive mx-auto mb-4" />
+            <h2 className="text-lg md:text-xl font-semibold mb-2">Failed to load configuration</h2>
+            <p className="text-sm md:text-base text-muted-foreground">
               Could not connect to Supervisor. Please check your configuration.
             </p>
           </CardContent>
@@ -28,11 +28,11 @@ export default function ConfigPage() {
   }
 
   return (
-    <div className="space-y-6">
-      <div className="flex items-center justify-between">
+    <div className="space-y-4 md:space-y-6">
+      <div className="flex flex-col sm:flex-row items-start sm:items-center justify-between gap-4">
         <div>
-          <h1 className="text-3xl font-bold">Configuration</h1>
-          <p className="text-muted-foreground mt-1">
+          <h1 className="text-2xl sm:text-3xl font-bold">Configuration</h1>
+          <p className="text-sm md:text-base text-muted-foreground mt-1">
             Manage process configurations and supervisor settings
           </p>
         </div>
@@ -65,8 +65,8 @@ export default function ConfigPage() {
           <ConfigTable configs={configs} />
         ) : (
           <Card>
-            <CardContent className="p-12 text-center">
-              <p className="text-muted-foreground">No process configurations found</p>
+            <CardContent className="p-8 md:p-12 text-center">
+              <p className="text-sm md:text-base text-muted-foreground">No process configurations found</p>
             </CardContent>
           </Card>
         )}