Add Unicode-safe rendering, sanitization, and font fallbacks

[chimbly]

Summary

• add Unicode-aware text sanitization and grapheme-safe truncation
• refactor label rendering with script fallback fonts and bounded font sizing
• harden web/CLI/RFID input handling and request-size guardrails
• improve printer/logo error resilience and keep rendering working when Wand/ImageMagick is unavailable
• add Unicode/security-focused tests for sanitizer, printer rendering, web flow, and RFID behavior

Notes

• includes bundled fallback fonts for broader script coverage (Arabic, Hebrew, CJK, Hangul, Ethiopic, emoji/symbol paths)
• generated test PNG outputs were intentionally not committed