Run the Main Workflow

Test the application as a user would use it.

Start with the existing board and check these actions in order:

1. open the Add Task modal
2. close it without submitting
3. create a task in To Do
4. create another task directly in In Progress
5. drag a task into Done
6. delete a task
7. refresh the page

After each action, look at both the cards and the column counts.

The expected pattern is:

action
  ↓
tasks changes
  ↓
renderTasks()
  ↓
board and counts match state

After the refresh, the saved state should produce the same board you had before reloading.

Checkpoint

Complete the entire sequence without the board becoming inconsistent.

If one step fails, fix that step before continuing. Do not add new features while debugging the existing flow.