Fix NLLB-200 tokenizer and add .dockerignore

- Fixed NLLB-200 tokenizer forced_bos_token_id issue
  - Changed from lang_code_to_id to convert_tokens_to_ids
- Added .dockerignore to exclude models directory from Docker build
  - Prevents disk space issues during build
  - Models are loaded at runtime via volume mount
- Both M2M100 and NLLB-200 models tested and working

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,42 @@
+# Python
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+.Python
+*.egg-info/
+dist/
+build/
+
+# Virtual environments
+venv/
+env/
+ENV/
+
+# Models cache (will be mounted as volume)
+models/
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+
+# Git
+.git/
+.gitignore
+
+# Documentation
+README.md
+CLAUDE.md
+*.md
+
+# Environment
+.env
+.env.local
+.env.*.local
+
+# Docker
+.dockerignore
+Dockerfile
+docker-compose.yml