Title: Add internationalization (i18n) support for puzzle text and UI strings

[Mkalbani]

Description

All user-facing strings (prompts, hints, error messages, TUI labels) are currently hardcoded in English. Add an i18n layer so contributors can add translations without touching game logic.

Acceptance Criteria

• fluent or rust-i18n integrated for string management
• All hardcoded UI/puzzle strings extracted into a locales/en.ftl (or equivalent) resource file
• --lang <code> CLI flag selects locale, falling back to English if missing
• At least one additional locale (e.g. fr or es) added as a working example
• CONTRIBUTING.md documents how to add a new locale file

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. I’ll prioritize this immediately and ensure a reliable solution is delivered as soon as possible. Thank you!

[ebubeb683-ship-it]

I am interested in working on this issue. I understand the requirements and can provide a solution promptly.

[jaynomyaro]

Hi! I’m a full-stack developer with a strong blockchain background, and I’m confident I can resolve this issue quickly and effectively. I’ll deliver a clean, reliable solution with immediate attention to detail, ensuring it’s completed as soon as possible. Please assign it to me—I’m ready to get started right away.

[jaynomyaro]

Hi! I’m a full-stack developer with a strong blockchain background, and I’m confident I can resolve this issue quickly and effectively. I’ll deliver a clean, reliable solution with immediate attention to detail, ensuring it’s completed as soon as possible. Please assign it to me—I’m ready to get started right away.

[grantfox-oss]

🦊 GrantFox — @ebubeb683-ship-it has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #31)
2. Your PR will be reviewed by the ThinknetCollective maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@ebubeb683-ship-it's PR #38 was approved and merged by @Mkalbani.

🏆 @ebubeb683-ship-it: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (156 total points). Track your full progress on GrantFox.

👏 Great work, @ebubeb683-ship-it! Keep contributing to ThinknetCollective.