Remove remaining status_id references after in_progress migration

- Remove Preload("Status") from worker handler and repositories
- Update seeds to use in_progress boolean instead of status_id
- Remove task_taskstatus table creation from lookup seeds
- Update documentation to reflect in_progress boolean pattern

Fixes notification worker error:
"Status: unsupported relations for schema Task"

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docs/TASK_KANBAN_LOGIC.md

@@ -103,12 +103,12 @@ if len(task.Completions) > 0 {
 
 ### 3. In Progress
 ```go
-if task.Status != nil && task.Status.Name == "In Progress" {
+if task.InProgress {
     inProgress = append(inProgress, task)
     continue
 }
 ```
-- **Condition**: Task's status name is exactly `"In Progress"`
+- **Condition**: Task's `in_progress` boolean is `true`
 - **Button Types**: `edit`, `complete`, `cancel`
 - **Rationale**: In-progress tasks can be edited, marked complete, or cancelled if work is abandoned