fix: mobile layout — prevent horizontal overflow on notifications page

- AuthGuard: switch outer shell from h-dvh to fixed inset-0 so the
  container always matches the visual viewport regardless of Android
  Chrome address-bar state; add min-w-0 to content column so flex
  children (e.g. long ntfy URL input) cannot force the column wider
  than the viewport
- Notifications page: add overflow-x-auto + shrink-0 to both tab bars
  so button overflow scrolls within the bar instead of escaping to the
  page; add min-w-0 to all inline label/hint div pairs in
  ModeFilterSection and Discovery so they shrink correctly in flex
  layout; add break-all to bill title line-clamp paragraph

Authored by: Jack Levy

frontend/app/notifications/page.tsx

@@ -126,21 +126,21 @@ function ModeFilterSection({
         <input type="checkbox" checked={!!filters["new_document"]}
           onChange={(e) => onChange({ ...filters, new_document: e.target.checked })}
           className="mt-0.5 rounded" />
-        <div><span className="text-sm">New bill text</span><span className="text-xs text-muted-foreground ml-2">The full text of the bill is published</span></div>
+        <div className="min-w-0"><span className="text-sm">New bill text</span><span className="text-xs text-muted-foreground ml-2">The full text of the bill is published</span></div>
       </label>
 
       <label className="flex items-start gap-3 py-1.5 cursor-pointer">
         <input type="checkbox" checked={!!filters["new_amendment"]}
           onChange={(e) => onChange({ ...filters, new_amendment: e.target.checked })}
           className="mt-0.5 rounded" />
-        <div><span className="text-sm">Amendment filed</span><span className="text-xs text-muted-foreground ml-2">An amendment is filed against the bill</span></div>
+        <div className="min-w-0"><span className="text-sm">Amendment filed</span><span className="text-xs text-muted-foreground ml-2">An amendment is filed against the bill</span></div>
       </label>
 
       <div className="py-1.5">
         <label className="flex items-start gap-3 cursor-pointer">
           <input ref={milestoneCheckRef} type="checkbox" checked={milestoneState === "on"}
             onChange={toggleMilestones} className="mt-0.5 rounded" />
-          <div><span className="text-sm font-medium">Milestones</span><span className="text-xs text-muted-foreground ml-2">Select all milestone types</span></div>
+          <div className="min-w-0"><span className="text-sm font-medium">Milestones</span><span className="text-xs text-muted-foreground ml-2">Select all milestone types</span></div>
         </label>
         <div className="ml-6 mt-1 space-y-0.5">
           {(["vote", "presidential", "committee_report", "calendar", "procedural"] as const).map((k) => {
@@ -150,7 +150,7 @@ function ModeFilterSection({
                 <input type="checkbox" checked={!!filters[k]}
                   onChange={(e) => onChange({ ...filters, [k]: e.target.checked })}
                   className="mt-0.5 rounded" />
-                <div><span className="text-sm">{row.label}</span><span className="text-xs text-muted-foreground ml-2">{row.hint}</span></div>
+                <div className="min-w-0"><span className="text-sm">{row.label}</span><span className="text-xs text-muted-foreground ml-2">{row.hint}</span></div>
               </label>
             );
           })}
@@ -484,7 +484,7 @@ export default function NotificationsPage() {
         </div>
 
         {/* Channel tab bar */}
-        <div className="flex gap-0 border-b border-border -mx-6 px-6">
+        <div className="flex gap-0 border-b border-border -mx-6 px-6 overflow-x-auto">
           {([
             { key: "ntfy", label: "ntfy", icon: Bell, active: settings?.ntfy_enabled },
             { key: "email", label: "Email", icon: Mail, active: settings?.email_enabled },
@@ -494,7 +494,7 @@ export default function NotificationsPage() {
             <button
               key={key}
               onClick={() => setActiveChannelTab(key)}
-              className={`flex items-center gap-1.5 px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
+              className={`shrink-0 flex items-center gap-1.5 px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
                 activeChannelTab === key
                   ? "border-primary text-foreground"
                   : "border-transparent text-muted-foreground hover:text-foreground"
@@ -688,12 +688,12 @@ export default function NotificationsPage() {
         </div>
 
         {/* Tab bar */}
-        <div className="flex gap-0 border-b border-border">
+        <div className="flex gap-0 border-b border-border overflow-x-auto">
           {MODES.map((mode) => (
             <button
               key={mode.key}
               onClick={() => setActiveFilterTab(mode.key as ModeKey)}
-              className={`px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
+              className={`shrink-0 px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
                 activeFilterTab === mode.key
                   ? "border-primary text-foreground"
                   : "border-transparent text-muted-foreground hover:text-foreground"
@@ -704,7 +704,7 @@ export default function NotificationsPage() {
           ))}
           <button
             onClick={() => setActiveFilterTab("discovery")}
-            className={`px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
+            className={`shrink-0 px-4 py-2 text-sm font-medium transition-colors border-b-2 -mb-px ${
               activeFilterTab === "discovery"
                 ? "border-primary text-foreground"
                 : "border-transparent text-muted-foreground hover:text-foreground"
@@ -749,7 +749,7 @@ export default function NotificationsPage() {
                     <input type="checkbox" checked={!!enabled}
                       onChange={(e) => setDiscoveryFilters((prev) => ({ ...prev, [src.key]: { ...prev[src.key], enabled: e.target.checked } }))}
                       className="rounded" />
-                    <div>
+                    <div className="min-w-0">
                       <span className="text-sm font-medium">Notify me about bills from member follows</span>
                       <span className="text-xs text-muted-foreground ml-2">{src.description}</span>
                     </div>
@@ -807,7 +807,7 @@ export default function NotificationsPage() {
                     <input type="checkbox" checked={!!enabled}
                       onChange={(e) => setDiscoveryFilters((prev) => ({ ...prev, [src.key]: { ...prev[src.key], enabled: e.target.checked } }))}
                       className="rounded" />
-                    <div>
+                    <div className="min-w-0">
                       <span className="text-sm font-medium">Notify me about bills from topic follows</span>
                       <span className="text-xs text-muted-foreground ml-2">{src.description}</span>
                     </div>
@@ -1062,7 +1062,7 @@ export default function NotificationsPage() {
                   <span className="text-xs text-muted-foreground ml-auto">{timeAgo(event.created_at)}</span>
                 </div>
                 {billTitle && (
-                  <p className="text-xs text-muted-foreground mt-0.5 line-clamp-1">{billTitle}</p>
+                  <p className="text-xs text-muted-foreground mt-0.5 line-clamp-1 break-all">{billTitle}</p>
                 )}
                 {(() => {
                   const src = p.source as string | undefined;

frontend/components/shared/AuthGuard.tsx

@@ -42,7 +42,7 @@ export function AuthGuard({ children }: { children: React.ReactNode }) {
 
   // Authenticated or guest browsing: render the full app shell
   return (
-    <div className="flex h-dvh bg-background">
+    <div className="fixed inset-0 flex overflow-hidden bg-background">
       {/* Desktop sidebar — hidden on mobile */}
       <div className="hidden md:flex">
         <Sidebar />
@@ -59,7 +59,7 @@ export function AuthGuard({ children }: { children: React.ReactNode }) {
       )}
 
       {/* Content column */}
-      <div className="flex-1 flex flex-col min-h-0">
+      <div className="flex-1 flex flex-col min-h-0 min-w-0">
         <MobileHeader onMenuClick={() => setDrawerOpen(true)} />
         <main className="flex-1 overflow-auto">
           <div className="container mx-auto px-4 md:px-6 py-6 max-w-7xl">