Make the project start more reliably in the current Windows bash setup, add a safe root .env.example for onboarding, and lower the backend Python floor to 3.11 to match the validated local environment.
Normalize uploaded documents into structured markdown, add clearer parser
errors for missing dependencies, and cover the ingestion flow with
backend tests. This also replaces deprecated UTC timestamp helpers in
the touched backend paths so the knowledge pipeline stays warning-free.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
