Improve sharing visibility: member count on cards, task assignment toast

- Add member_count to ProjectResponse via model_validator (computed from
  eagerly loaded members relationship). Shows on ProjectCard for both
  owners ("2 members") and shared users ("Shared with you").
- Fix share button badge positioning (add relative class).
- Add dedicated showTaskAssignedToast with blue ClipboardList icon,
  "View Project" action button, and 15s duration.
- Wire task_assigned into both initial-load and new-notification toast
  dispatch flows in NotificationToaster.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/schemas/project.py

@@ -1,4 +1,4 @@
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, model_validator
 from datetime import datetime, date
 from typing import Optional, List, Literal
 from app.schemas.project_task import ProjectTaskResponse
@@ -37,12 +37,37 @@ class ProjectResponse(BaseModel):
     color: Optional[str]
     due_date: Optional[date]
     is_tracked: bool
+    member_count: int = 0
     created_at: datetime
     updated_at: datetime
     tasks: List[ProjectTaskResponse] = []
 
     model_config = ConfigDict(from_attributes=True)
 
+    @model_validator(mode="before")
+    @classmethod
+    def compute_member_count(cls, data):  # type: ignore[override]
+        """Compute member_count from eagerly loaded members relationship."""
+        if hasattr(data, "members"):
+            try:
+                data = dict(
+                    id=data.id,
+                    user_id=data.user_id,
+                    name=data.name,
+                    description=data.description,
+                    status=data.status,
+                    color=data.color,
+                    due_date=data.due_date,
+                    is_tracked=data.is_tracked,
+                    member_count=len([m for m in data.members if m.status == "accepted"]),
+                    created_at=data.created_at,
+                    updated_at=data.updated_at,
+                    tasks=data.tasks,
+                )
+            except Exception:
+                pass  # If members aren't loaded, default to 0
+        return data
+
 
 class TrackedTaskResponse(BaseModel):
     id: int

frontend/src/components/notifications/NotificationToaster.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useRef, useCallback } from 'react';
 import { toast } from 'sonner';
-import { Check, X, Bell, UserPlus, Calendar, Clock, FolderKanban } from 'lucide-react';
+import { Check, X, Bell, UserPlus, Calendar, Clock, FolderKanban, ClipboardList } from 'lucide-react';
 import { useQueryClient } from '@tanstack/react-query';
 import { useNotifications } from '@/hooks/useNotifications';
 import { useConnections } from '@/hooks/useConnections';
@@ -173,7 +173,7 @@ export default function NotificationToaster() {
       initializedRef.current = true;
 
       // Toast actionable unread notifications on login so the user can act immediately
-      const actionableTypes = new Set(['connection_request', 'calendar_invite', 'event_invite', 'project_invite']);
+      const actionableTypes = new Set(['connection_request', 'calendar_invite', 'event_invite', 'project_invite', 'task_assigned']);
       const actionable = notifications.filter(
         (n) => !n.is_read && actionableTypes.has(n.type),
       );
@@ -189,6 +189,8 @@ export default function NotificationToaster() {
           showEventInviteToast(notification);
         } else if (notification.type === 'project_invite' && notification.data) {
           showProjectInviteToast(notification);
+        } else if (notification.type === 'task_assigned' && notification.data) {
+          showTaskAssignedToast(notification);
         }
       });
       return;
@@ -231,6 +233,8 @@ export default function NotificationToaster() {
         showEventInviteToast(notification);
       } else if (notification.type === 'project_invite' && notification.data) {
         showProjectInviteToast(notification);
+      } else if (notification.type === 'task_assigned' && notification.data) {
+        showTaskAssignedToast(notification);
       } else {
         toast(notification.title || 'New Notification', {
           description: notification.message || undefined,
@@ -399,6 +403,54 @@ export default function NotificationToaster() {
     );
   };
 
+  const showTaskAssignedToast = (notification: AppNotification) => {
+    const data = notification.data as Record<string, unknown> | undefined;
+    const projectId = data?.project_id as number | undefined;
+    const toastKey = `task-assigned-${notification.id}`;
+
+    toast.custom(
+      (id) => (
+        <div className="w-[356px] rounded-lg border border-border bg-card p-4 shadow-lg">
+          <div className="flex items-start gap-3">
+            <div className="h-9 w-9 rounded-full bg-blue-500/15 flex items-center justify-center shrink-0">
+              <ClipboardList className="h-4 w-4 text-blue-400" />
+            </div>
+            <div className="flex-1 min-w-0">
+              <p className="text-sm font-medium text-foreground">Task Assigned</p>
+              <p className="text-xs text-muted-foreground mt-0.5">
+                {notification.message || 'You were assigned to a task'}
+              </p>
+              <div className="flex items-center gap-2 mt-3">
+                {projectId && (
+                  <button
+                    onClick={() => {
+                      toast.dismiss(id);
+                      markReadRef.current([notification.id]).catch(() => {});
+                      window.location.href = `/projects/${projectId}`;
+                    }}
+                    className="flex items-center gap-1 px-3 py-1.5 text-xs font-medium rounded-md bg-accent text-accent-foreground hover:bg-accent/90 transition-colors"
+                  >
+                    View Project
+                  </button>
+                )}
+                <button
+                  onClick={() => {
+                    toast.dismiss(id);
+                    markReadRef.current([notification.id]).catch(() => {});
+                  }}
+                  className="flex items-center gap-1 px-3 py-1.5 text-xs font-medium rounded-md text-muted-foreground hover:bg-card-elevated transition-colors"
+                >
+                  Dismiss
+                </button>
+              </div>
+            </div>
+          </div>
+        </div>
+      ),
+      { id: toastKey, duration: 15000 },
+    );
+  };
+
   const showProjectInviteToast = (notification: AppNotification) => {
     const data = notification.data as Record<string, unknown> | undefined;
     const projectId = data?.project_id as number | undefined;

frontend/src/components/projects/ProjectCard.tsx

@@ -100,10 +100,15 @@ export default function ProjectCard({ project }: ProjectCardProps) {
             Due {format(parseISO(project.due_date), 'MMM d, yyyy')}
           </div>
         )}
-        {isShared && (
+        {/* Sharing indicator — shows for both owner and shared users */}
+        {project.member_count > 0 && (
           <div className="flex items-center gap-1.5 text-xs text-muted-foreground mt-2">
             <Users className="h-3.5 w-3.5" />
-            <span>Shared with you</span>
+            <span>
+              {isShared
+                ? 'Shared with you'
+                : `${project.member_count} member${project.member_count !== 1 ? 's' : ''}`}
+            </span>
           </div>
         )}
       </CardContent>

frontend/src/components/projects/ProjectDetail.tsx

@@ -443,7 +443,7 @@ export default function ProjectDetail() {
         <Button
           variant="ghost"
           size="icon"
-          className="shrink-0 text-muted-foreground"
+          className="shrink-0 text-muted-foreground relative"
           onClick={() => setShowShareSheet(true)}
           title="Project members"
         >

frontend/src/types/index.ts

@@ -144,6 +144,7 @@ export interface Project {
   color?: string;
   due_date?: string;
   is_tracked: boolean;
+  member_count: number;
   created_at: string;
   updated_at: string;
   tasks: ProjectTask[];