feat: add workspace management features including member invitations and role updates

- Implemented API endpoints for managing workspace members (GET, POST, PATCH, DELETE).
- Added workspace creation and retrieval functionalities.
- Enhanced project model to associate with workspaces.
- Updated project member roles and access control logic.
- Created sign-out page and updated authentication flow.
- Modified header to include navigation to workspaces.
- Updated Prisma schema to include workspace and member models.
- Seed script updated to create demo workspaces and associated members.

app/api/workspaces/[workspaceId]/route.ts

@@ -0,0 +1,155 @@
+import { NextRequest, NextResponse } from 'next/server';
+import { db } from '@/lib/db';
+import { auth } from '@/lib/auth';
+
+type RouteParams = { params: Promise<{ workspaceId: string }> };
+
+// Helper to check workspace access
+async function checkWorkspaceAccess(workspaceId: string, userId: string) {
+    const workspace = await db.workspace.findUnique({
+        where: { id: workspaceId },
+        include: {
+            members: { where: { userId } },
+        },
+    });
+
+    if (!workspace) return { workspace: null, role: null, isOwner: false, isAdmin: false };
+
+    const isOwner = workspace.ownerId === userId;
+    const membership = workspace.members[0];
+    const role = isOwner ? 'OWNER' : membership?.role || null;
+
+    return {
+        workspace,
+        role,
+        isOwner,
+        isAdmin: isOwner || role === 'ADMIN',
+    };
+}
+
+// GET /api/workspaces/[workspaceId] - Get a single workspace
+export async function GET(request: NextRequest, { params }: RouteParams) {
+    try {
+        const session = await auth();
+        const { workspaceId } = await params;
+
+        if (!session?.user?.id) {
+            return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+        }
+
+        const workspace = await db.workspace.findUnique({
+            where: { id: workspaceId },
+            include: {
+                owner: { select: { id: true, name: true, image: true } },
+                members: {
+                    include: {
+                        user: { select: { id: true, name: true, image: true } },
+                    },
+                },
+                projects: {
+                    orderBy: { updatedAt: 'desc' },
+                    include: {
+                        _count: { select: { videos: true, members: true } },
+                    },
+                },
+                _count: { select: { projects: true, members: true } },
+            },
+        });
+
+        if (!workspace) {
+            return NextResponse.json({ error: 'Workspace not found' }, { status: 404 });
+        }
+
+        // Check access
+        const isOwner = session?.user?.id === workspace.ownerId;
+        const isMember = workspace.members.some(m => m.userId === session?.user?.id);
+
+        if (!isOwner && !isMember) {
+            return NextResponse.json({ error: 'Access denied' }, { status: 403 });
+        }
+
+        return NextResponse.json(workspace);
+    } catch (error) {
+        console.error('Error fetching workspace:', error);
+        return NextResponse.json(
+            { error: 'Failed to fetch workspace' },
+            { status: 500 }
+        );
+    }
+}
+
+// PATCH /api/workspaces/[workspaceId] - Update a workspace
+export async function PATCH(request: NextRequest, { params }: RouteParams) {
+    try {
+        const session = await auth();
+        const { workspaceId } = await params;
+
+        if (!session?.user?.id) {
+            return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+        }
+
+        const { isAdmin } = await checkWorkspaceAccess(workspaceId, session.user.id);
+        if (!isAdmin) {
+            return NextResponse.json({ error: 'Access denied' }, { status: 403 });
+        }
+
+        const body = await request.json();
+        const { name, description } = body;
+
+        const updateData: Record<string, unknown> = {};
+        if (name !== undefined) updateData.name = name.trim();
+        if (description !== undefined) updateData.description = description?.trim() || null;
+
+        const workspace = await db.workspace.update({
+            where: { id: workspaceId },
+            data: updateData,
+            include: {
+                owner: { select: { id: true, name: true, image: true } },
+                _count: { select: { projects: true, members: true } },
+            },
+        });
+
+        return NextResponse.json(workspace);
+    } catch (error) {
+        console.error('Error updating workspace:', error);
+        return NextResponse.json(
+            { error: 'Failed to update workspace' },
+            { status: 500 }
+        );
+    }
+}
+
+// DELETE /api/workspaces/[workspaceId] - Delete a workspace
+export async function DELETE(request: NextRequest, { params }: RouteParams) {
+    try {
+        const session = await auth();
+        const { workspaceId } = await params;
+
+        if (!session?.user?.id) {
+            return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
+        }
+
+        const { isOwner, workspace } = await checkWorkspaceAccess(workspaceId, session.user.id);
+
+        if (!workspace) {
+            return NextResponse.json({ error: 'Workspace not found' }, { status: 404 });
+        }
+
+        if (!isOwner) {
+            return NextResponse.json(
+                { error: 'Only the workspace owner can delete it' },
+                { status: 403 }
+            );
+        }
+
+        await db.workspace.delete({ where: { id: workspaceId } });
+
+        return NextResponse.json({ success: true, message: 'Workspace deleted' });
+    } catch (error) {
+        console.error('Error deleting workspace:', error);
+        return NextResponse.json(
+            { error: 'Failed to delete workspace' },
+            { status: 500 }
+        );
+    }
+}