feat: improve mobile responsiveness across UI components

- Add responsive layout for action buttons (stack vertically on mobile, horizontal on sm+)
- Adjust card max-widths for better mobile display (LocationCard, MultiBillEdit)
- Improve button text sizing with responsive classes (text-sm on mobile, text-xs on sm+)
- Remove width constraints on file inputs and info boxes for full-width mobile layout
- Fine-tune icon positioning for better visual alignment

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

app/ui/MonthLocationList.tsx

@@ -132,10 +132,10 @@ export const MonthLocationList:React.FC<MonthLocationListProps  > = ({
                                 locations.map((location, ix) => <LocationCard key={`location-${location._id}`} location={location} currency={userSettings?.currency} />)
                                 : null
                         }
-                        <div className="flex gap-2 justify-center">
-                        <AddLocationButton yearMonth={yearMonth} />
-                        <PrintButton yearMonth={yearMonth} />
-                        <MultiBillEditButton yearMonth={yearMonth} />
+                        <div className="flex flex-col sm:flex-row sm:gap-2 justify-center">
+                            <AddLocationButton yearMonth={yearMonth} />
+                            <PrintButton yearMonth={yearMonth} />
+                            <MultiBillEditButton yearMonth={yearMonth} />
                         </div>
                     </MonthCard>
                 )