Initial implementation: multi-tenant Kanban board (Phase 1)

Complete Phase 1 foundation with working board, column, and card CRUD:
- SvelteKit + TypeScript + Tailwind CSS v4 + adapter-node
- Full Prisma schema with 18 tables (tenants, users, boards, columns, cards, etc.)
- Multi-tenant architecture with hostname-based tenant resolution
- Email/password auth with bcrypt + session cookies
- Board/Column/Card API routes with full CRUD
- Fractional indexing for drag-and-drop ordering
- Board view with svelte-dnd-action for column and card drag-and-drop
- Card modal with inline editing
- Auth pages (login, register)
- Board listing with create form
- RLS policies SQL script for tenant isolation
- Prisma RLS client extensions (forTenant/bypassRLS)
- Permission helpers (canEditBoard, canManageMembers, etc.)
- Socket.IO server setup (dev Vite plugin + production Express server)
- Client-side socket store for real-time updates
- Docker Compose (app + PostgreSQL 16) + multi-stage Dockerfile
- Database seed script (default tenant + admin user)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/routes/api/boards/+server.ts

@@ -0,0 +1,74 @@
+import { json, error } from '@sveltejs/kit';
+import type { RequestHandler } from './$types.js';
+import { prisma } from '$lib/server/db.js';
+import { boardSchema } from '$lib/server/validation.js';
+
+// List boards for current tenant
+export const GET: RequestHandler = async ({ locals }) => {
+	const tenant = locals.tenant;
+	if (!tenant) throw error(400, 'Unknown tenant');
+
+	const where: Record<string, unknown> = { tenantId: tenant.id, archived: false };
+
+	// If not logged in, only show public boards
+	if (!locals.user) {
+		where.visibility = 'PUBLIC';
+	} else {
+		// Show boards user is a member of + public boards
+		where.OR = [
+			{ visibility: 'PUBLIC' },
+			{ members: { some: { userId: locals.user.id } } }
+		];
+		delete where.visibility;
+	}
+
+	const boards = await prisma.board.findMany({
+		where,
+		include: {
+			members: {
+				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+			},
+			_count: { select: { columns: true } }
+		},
+		orderBy: { updatedAt: 'desc' }
+	});
+
+	return json({ boards });
+};
+
+// Create a new board
+export const POST: RequestHandler = async ({ request, locals }) => {
+	const tenant = locals.tenant;
+	if (!tenant) throw error(400, 'Unknown tenant');
+	if (!locals.user) throw error(401, 'Not authenticated');
+
+	const body = await request.json();
+	const result = boardSchema.safeParse(body);
+	if (!result.success) {
+		return json({ error: result.error.issues[0].message }, { status: 400 });
+	}
+
+	const { title, description, visibility } = result.data;
+
+	const board = await prisma.board.create({
+		data: {
+			tenantId: tenant.id,
+			title,
+			description,
+			visibility,
+			members: {
+				create: {
+					userId: locals.user.id,
+					role: 'OWNER'
+				}
+			}
+		},
+		include: {
+			members: {
+				include: { user: { select: { id: true, name: true, avatarUrl: true } } }
+			}
+		}
+	});
+
+	return json({ board }, { status: 201 });
+};