Add a "Counter" Activity Type

Griply currently supports Habits and Repeating Tasks, but there is a gap for activities that users simply want to count and analyze over time.

I would like a new activity type called "Counter" (or similar).

A Counter would allow users to log completions and track statistics exactly like Habits currently do, including history, charts, and total completions. However, it would not be treated as a Habit and would not appear in habit-related features. Likewise, it would not behave as a Task, since there is no concept of completion requirements, due dates, or overdue states.

Examples:

• Glasses of water consumed

• Pomodoro sessions completed

• Push-up sets performed

• Books finished

• Practice sessions logged

The goal is to provide a simple quantitative tracker for activities where users care about frequency and statistics, but do not want the activity categorized as either a Habit or a Task.