Refactor: Centralized Regex Patterns and Type-Safe i18n Implementation

[thomas-vilte]

Overview

This PR implements a significant refactoring of the internal regex handling and internationalization (i18n) systems. I centralized all regular expressions into a dedicated package and replaced generic map-based translation data with structured types to enhance maintainability and runtime stability.

Key Changes

• Regex Centralization: I created the internal/regex package, consolidating patterns for Conventional Commits, SemVer, GitHub/Jira links, and Go modules. This eliminates redundant regexp.MustCompile calls across the codebase.
• Type-Safe Translations: I refactored the i18n.GetMessage method and its callers to use specific struct types instead of map[string]interface{}. This ensures that translation templates receive the correct fields at compile-time.
• Standardized Progress Events: I introduced a concrete ProgressData struct in the models package to replace generic maps in ProgressEvent, providing a consistent schema for PR and commit generation feedback.
• Localization Updates: I expanded the English and Spanish translation files to include missing keys for release management, editor handling, and Gemini API validation.
• Cleanup: I removed the deprecated .mailmap file and corrected repository casing in the version checker to match the canonical GitHub path.

Technical Impact

• Performance: Pre-compiling regex patterns in a single package reduces initialization overhead and memory allocations during command execution.
• Robustness: Transitioning to structured data for i18n prevents common runtime bugs where translation keys are missing or incorrectly typed in the template data.
• Maintainability: Centralizing patterns like GitHubClosedLink and JiraTicket makes it easier to update logic for different VCS or ticket providers in one place.