Commit MWS backend source tree

The ASP.NET Core solution (mws.api/mws.application/mws.domain/
mws.infrastructure) existed only as untracked working files. Adding
it to version control, plus a .gitignore for build output and local
tooling directories, so the CQRS/mediator refactor plan has a real
git history to branch and diff against.

mws.infrastructure/Persistence/AppDbContext.cs

@@ -0,0 +1,25 @@
+using Microsoft.EntityFrameworkCore;
+using Mws.Domain.Documents;
+using Mws.Domain.Projects;
+using Mws.Domain.Roles;
+using Mws.Domain.Tasks;
+using Mws.Domain.Users;
+
+namespace Mws.Infrastructure.Persistence;
+
+public class AppDbContext(DbContextOptions<AppDbContext> options) : DbContext(options)
+{
+    public DbSet<User> Users => Set<User>();
+    public DbSet<Project> Projects => Set<Project>();
+    public DbSet<ProjectMember> ProjectMembers => Set<ProjectMember>();
+    public DbSet<ProjectMemberPermission> ProjectMemberPermissions => Set<ProjectMemberPermission>();
+    public DbSet<Document> Documents => Set<Document>();
+    public DbSet<TaskItem> Tasks => Set<TaskItem>();
+    public DbSet<Role> Roles => Set<Role>();
+    public DbSet<RolePermission> RolePermissions => Set<RolePermission>();
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        modelBuilder.ApplyConfigurationsFromAssembly(typeof(AppDbContext).Assembly);
+    }
+}