fix: mobile goal UX — bottom-sheet dialog, keyboard-safe target button, capacitor safe-top for overlays

- the goal dialog renders as the shared MobileOverlayPanel bottom sheet
  on mobile instead of a centered dialog
- tapping the target button to ARM keeps the soft keyboard open (the next
  message is the objective; same guard as the attachment/mic buttons),
  while opening the manage sheet lets the keyboard close as usual
- capacitor: bottom-sheet overlays cap their height by the keyboard inset
  AND the top safe area — with the keyboard raised while typing inside a
  sheet, 100dvh does not shrink (native resize is off) and the panel could
  slide under the notch/status bar; applies to every MobileOverlayPanel

packages/ui/src/components/chat/SessionGoalButton.tsx

@@ -76,6 +76,20 @@ export const SessionGoalButton: React.FC<SessionGoalButtonProps> = React.memo(({
       type="button"
       className={cn(footerIconButtonClass, colorClass)}
       onClick={handleClick}
+      // Same guard as PermissionAutoAcceptButton, but only for the ARM
+      // toggle: arming happens mid-typing (the next message IS the
+      // objective), so that tap must not dismiss the soft keyboard or
+      // trigger the Android keyboard-close relayout that moves the button
+      // before the click lands. Opening the manage sheet (goal exists) is a
+      // context switch — there the keyboard should close as usual.
+      onMouseDown={(event) => {
+        if (!goal) event.preventDefault();
+      }}
+      onPointerDownCapture={(event) => {
+        if (!goal && event.pointerType === 'touch') {
+          event.preventDefault();
+        }
+      }}
       aria-label={label}
       aria-pressed={isEngaged}
       {...(withTooltip ? {} : { title: label })}

packages/ui/src/components/chat/SessionGoalDialog.tsx

@@ -18,6 +18,8 @@ import {
 import { sessionGoalStatusColor, sessionGoalStatusLabelKey } from '@/lib/sessionGoalPresentation';
 import { clearSessionGoal, setSessionGoal } from '@/lib/sessionGoalActions';
 import { useI18n } from '@/lib/i18n';
+import { MobileOverlayPanel } from '@/components/ui/MobileOverlayPanel';
+import { useUIStore } from '@/stores/useUIStore';
 
 interface SessionGoalDialogProps {
   open: boolean;
@@ -31,6 +33,7 @@ interface SessionGoalDialogProps {
 // (pause/resume/complete/clear) once a goal exists.
 export function SessionGoalDialog({ open, onOpenChange, sessionId, directory }: SessionGoalDialogProps) {
   const { t } = useI18n();
+  const isMobile = useUIStore((state) => state.isMobile);
   const { goal } = useSessionGoal(sessionId, directory);
   const objectiveContent = useGoalObjectiveContent(sessionId, goal);
 
@@ -86,13 +89,9 @@ export function SessionGoalDialog({ open, onOpenChange, sessionId, directory }:
     true,
   );
 
-  return (
-    <Dialog open={open} onOpenChange={onOpenChange}>
-      <DialogContent className="max-w-lg">
-        <DialogHeader>
-          <DialogTitle>{goal ? t('chat.goal.dialog.titleManage') : t('chat.goal.dialog.titleCreate')}</DialogTitle>
-        </DialogHeader>
+  const title = goal ? t('chat.goal.dialog.titleManage') : t('chat.goal.dialog.titleCreate');
 
+  const body = (
         <div className="space-y-3">
           {goal && (
             <div className="space-y-1 p-2 rounded-lg" style={{ backgroundColor: 'var(--surface-elevated)' }}>
@@ -193,6 +192,25 @@ export function SessionGoalDialog({ open, onOpenChange, sessionId, directory }:
             </div>
           </div>
         </div>
+  );
+
+  // Mobile renders the shared bottom-sheet overlay instead of a centered
+  // dialog — same pattern as model controls and the session status panel.
+  if (isMobile) {
+    return (
+      <MobileOverlayPanel open={open} title={title} onClose={() => onOpenChange(false)}>
+        {body}
+      </MobileOverlayPanel>
+    );
+  }
+
+  return (
+    <Dialog open={open} onOpenChange={onOpenChange}>
+      <DialogContent className="max-w-lg">
+        <DialogHeader>
+          <DialogTitle>{title}</DialogTitle>
+        </DialogHeader>
+        {body}
       </DialogContent>
     </Dialog>
   );