v0.4.0 - honest drills, week streaks

• Starting an unaided drill while a known AI assistant is running (Copilot, Cursor, Claude, Windsurf, Codeium, Tabnine, Ollama, LM Studio, ChatGPT, Aider) now warns you by name. Warned, never blocked.
• Week streaks: consecutive weeks with 2+ unaided reps, shown in atrophy stats and as a dashboard tile. An in-progress week never breaks your streak early.
• All text is now em-dash free.