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/handlers/task_handler.go

@@ -517,16 +517,6 @@ func (h *TaskHandler) GetPriorities(c *gin.Context) {
 	c.JSON(http.StatusOK, priorities)
 }
 
-// GetStatuses handles GET /api/tasks/statuses/
-func (h *TaskHandler) GetStatuses(c *gin.Context) {
-	statuses, err := h.taskService.GetStatuses()
-	if err != nil {
-		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
-		return
-	}
-	c.JSON(http.StatusOK, statuses)
-}
-
 // GetFrequencies handles GET /api/tasks/frequencies/
 func (h *TaskHandler) GetFrequencies(c *gin.Context) {
 	frequencies, err := h.taskService.GetFrequencies()