Enable Customizable Confirmation Options with Clear Feedback for Unrecognized Inputs

Currently, when pacman prompts for confirmation (e.g., when updating or executing commands), it expects the user to input 't' (for "tak" in Polish) to confirm. However, many users (including myself) are accustomed to using 'y' for "yes". When 'y' is entered, pacman treats it as a negative response ('no') and silently skips the action without any warning or notification.

**Proposed Solution:**
1. **Accept 'y' as a valid affirmative input:** Allow the use of 'y' alongside 't' to confirm actions.
2. **Configurability:** Introduce a configuration option where users can define which characters are treated as affirmative responses.
3. **Feedback:** If an unrecognized confirmation input is entered, provide a clear warning or prompt so the user is aware that the input was not accepted. (maybe prompt again?)

**Rationale:**
- **User Habits:** Many users are used to typing 'y' for confirmation, especially in environments where English is the primary language.
- **Improved UX:** Avoiding silent skips will prevent accidental omission of critical updates or commands.
- **Localization:** This change would cater to both Polish users and a broader international audience by aligning with common confirmation conventions.

The issue names no files or tests. Start by locating pacman’s confirmation prompt and configuration handling, then review existing input and localization behavior. Done means affirmative characters are configurable, “y” can be accepted alongside “t”, and unrecognized input receives clear feedback rather than being silently treated as negative.

Written by the indexing model from the issue text.