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/projects/route.ts

@@ -15,17 +15,32 @@ export async function GET(request: NextRequest) {
         const { searchParams } = new URL(request.url);
         const page = parseInt(searchParams.get('page') || '1');
         const limit = parseInt(searchParams.get('limit') || '10');
+        const workspaceId = searchParams.get('workspaceId');
         const skip = (page - 1) * limit;
 
+        // Build base filter: user is owner OR a member
+        const baseFilter: Record<string, unknown> = {
+            OR: [
+                { ownerId: session.user.id },
+                { members: { some: { userId: session.user.id } } },
+                // Also include projects in workspaces where the user is a workspace member
+                ...(workspaceId ? [] : [{
+                    workspace: {
+                        members: { some: { userId: session.user.id } },
+                    },
+                }]),
+            ],
+        };
+
+        // Filter by workspace if provided
+        if (workspaceId) {
+            baseFilter.workspaceId = workspaceId;
+        }
+
         // Get projects where user is owner OR a member
         const [projects, total] = await Promise.all([
             db.project.findMany({
-                where: {
-                    OR: [
-                        { ownerId: session.user.id },
-                        { members: { some: { userId: session.user.id } } },
-                    ],
-                },
+                where: baseFilter,
                 include: {
                     owner: { select: { id: true, name: true, image: true } },
                     _count: { select: { videos: true, members: true } },
@@ -35,12 +50,7 @@ export async function GET(request: NextRequest) {
                 take: limit,
             }),
             db.project.count({
-                where: {
-                    OR: [
-                        { ownerId: session.user.id },
-                        { members: { some: { userId: session.user.id } } },
-                    ],
-                },
+                where: baseFilter,
             }),
         ]);
 
@@ -72,7 +82,7 @@ export async function POST(request: NextRequest) {
         }
 
         const body = await request.json();
-        const { name, description, visibility } = body;
+        const { name, description, visibility, workspaceId } = body;
 
         if (!name || typeof name !== 'string' || name.trim().length === 0) {
             return NextResponse.json(
@@ -81,6 +91,13 @@ export async function POST(request: NextRequest) {
             );
         }
 
+        if (!workspaceId || typeof workspaceId !== 'string') {
+            return NextResponse.json(
+                { error: 'A workspace is required. Every project must belong to a workspace.' },
+                { status: 400 }
+            );
+        }
+
         // Generate URL-friendly slug
         const baseSlug = name
             .toLowerCase()
@@ -99,6 +116,26 @@ export async function POST(request: NextRequest) {
             attempts++;
         }
 
+        // Verify user has access to the workspace
+        const workspace = await db.workspace.findUnique({
+            where: { id: workspaceId },
+            include: { members: { where: { userId: session.user.id } } },
+        });
+
+        if (!workspace) {
+            return NextResponse.json({ error: 'Workspace not found' }, { status: 404 });
+        }
+
+        const isWsOwner = workspace.ownerId === session.user.id;
+        const isWsAdmin = workspace.members[0]?.role === 'ADMIN';
+
+        if (!isWsOwner && !isWsAdmin) {
+            return NextResponse.json(
+                { error: 'Only workspace owners and admins can create projects' },
+                { status: 403 }
+            );
+        }
+
         const project = await db.project.create({
             data: {
                 name: name.trim(),
@@ -106,6 +143,7 @@ export async function POST(request: NextRequest) {
                 slug,
                 visibility: visibility || ProjectVisibility.PRIVATE,
                 ownerId: session.user.id,
+                workspaceId,
             },
             include: {
                 owner: { select: { id: true, name: true, image: true } },