Task language detection and inheritance system

When a task is created and during generation of the title recognize the language of the task description and remember on the task row and the title should be in that language. Language of the prose is more important than the language of screenshots or attachments. Language should be shown in the task details. All epic subtasks inherit the language. All questions must use that language - both the runner is asking and the internal LLM when writing a simplified version. All artifacts must use the language of the task.

Task language detected with the title, stored on the row, editable in Details, inherited by epic subtasks, applied to runner prompts and question rewording. Quick gate green; PR #7667 merged (af60f59). Visual check done. Deploy superseded.