feat: add language support for wiki generation

[maxfrank76]

Add language support for wiki generation

This PR adds the ability to generate wiki documentation in a user‑specified language (e.g., Russian, Spanish, etc.) instead of always English. The language is read from .repowise/config.yaml (language: ru) and passed through the generation pipeline.

Changes

1. models.py: added language: str = "en" field to GenerationConfig.
2. init_cmd.py: loads language from config and passes it to GenerationConfig; also displays selected language in console.
3. orchestrator.py: added generation_config parameter to run_generation to preserve the original config (especially language) when creating a new GenerationConfig with adjusted max_concurrency.
4. page_generator.py:
   • Constructor accepts language and stores it as self._language.
   • _call_provider injects a language instruction into the system prompt if self._language != "en". The instruction tells the LLM to generate documentation in the specified language while keeping code, file paths, and symbol names unchanged.

How to test

1. Create .repowise/config.yaml with:

   provider: ollama
   model: qwen3.5:latest
   language: ru

2. Run repowise init (--force (or repowise update --all for existing wiki)).
3. The generated wiki pages should be in Russian (or your chosen language).

Notes

Default language is en.
Only descriptive text is translated; code blocks, file paths, and symbol names remain original.
Works with any provider (Anthropic, OpenAI, Gemini, Ollama) as long as the model supports multilingual output.