feat(tasking): add projects feature and restructure backend

- Restructure backend code into Tasking module with organized endpoints
  - Add Project and Sprint entities with database migrations
  - Implement CRUD endpoints for projects (create, get, rename, delete)
  - Refactor task endpoints into Tasking namespace
  - Add integration test suite with Testcontainers and Respawn
  - Refactor frontend to use Pinia stores with dedicated API clients
  - Add DueDatePicker and DueTimePicker components for task scheduling
  - Add environment configuration for API base URL
  - Add infrastructure setup scripts for Docker/Postgres

Tasker.Ui/.env.production

@@ -0,0 +1,5 @@
+# Production environment variables for Vite
+# Replace the URL below with your production API endpoint.
+# Vite only exposes variables prefixed with VITE_.
+
+VITE_API_BASE_URL=https://api.example.com/