refactor: consolidate task search logic into generic function

[LudoLoops]

Issue

Multiple functions perform nearly identical task lookups across the entire task directory:

Duplicate Functions:

• MarkTaskDone (task.go:106)
• MarkTaskInProgress (task.go:169)
• MarkTaskInProgressByTitle (task.go:233)
• IncrementPomodoroCountForActiveTask (task.go:297)

Each implements the same filepath.Walk logic with different predicates.

Refactor Opportunity

Create a generic search function:

func findTaskByPredicate(cfg config.Config, predicate func(*config.Task) bool) (*config.Task, string, error) {
    // Common walk logic
    // Call predicate(task) to check condition
}

Then simplify existing functions:

func MarkTaskDone(cfg config.Config, taskTitle string) {
    task, path, _ := findTaskByPredicate(cfg, func(t *config.Task) bool {
        return strings.EqualFold(t.Title, taskTitle)
    })
    // ...
}

Benefits

• Eliminates ~200 lines of duplicate code
• Single place to optimize search logic
• Easier maintenance

Impact

🟢 Low - Improvement only, no bug fix