Replace status_id with in_progress boolean field

- Remove task_statuses lookup table and StatusID foreign key
- Add InProgress boolean field to Task model
- Add database migration (005_replace_status_with_in_progress)
- Update all handlers, services, and repositories
- Update admin frontend to display in_progress as checkbox/boolean
- Remove Task Statuses tab from admin lookups page
- Update tests to use InProgress instead of StatusID
- Task categorization now uses InProgress for kanban column assignment

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

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

internal/task/scopes/scopes.go

@@ -73,22 +73,22 @@ func ScopeNotCompleted(db *gorm.DB) *gorm.DB {
 	)
 }
 
-// ScopeInProgress filters to tasks with status "In Progress".
+// ScopeInProgress filters to tasks marked as in progress.
 //
 // Predicate equivalent: IsInProgress(task)
 //
-// SQL: Joins task_taskstatus and filters by name = 'In Progress'
+// SQL: in_progress = true
 func ScopeInProgress(db *gorm.DB) *gorm.DB {
-	return db.Joins("LEFT JOIN task_taskstatus ON task_taskstatus.id = task_task.status_id").
-		Where("task_taskstatus.name = ?", "In Progress")
+	return db.Where("in_progress = ?", true)
 }
 
-// ScopeNotInProgress excludes tasks with status "In Progress".
+// ScopeNotInProgress excludes tasks marked as in progress.
 //
 // Predicate equivalent: !IsInProgress(task)
+//
+// SQL: in_progress = false
 func ScopeNotInProgress(db *gorm.DB) *gorm.DB {
-	return db.Joins("LEFT JOIN task_taskstatus ON task_taskstatus.id = task_task.status_id").
-		Where("task_taskstatus.name != ? OR task_taskstatus.name IS NULL", "In Progress")
+	return db.Where("in_progress = ?", false)
 }
 
 // =============================================================================