docs: remove VERTEX_API_KEY references from config/docs

fix(security+infra): Sprint Fix 1 — path traversal, docker-compose, CORS

fix(sprint-f4-f5): tests faux-positifs, frontend bugs, Dockerfile unique

fix(mistral): refactoring structurel complet du provider Mistral

fix(mistralai): detect v0.x package + force pip --upgrade in Dockerfile

fix(paths): analyse systémique et correction exhaustive des chemins en production

fix(profiles): add explicit PROFILES_DIR/PROMPTS_DIR env vars in Dockerfiles

feat(sprint5): frontend React minimal — visionneuse + 4 couches

feat(sprint5-session-a): Dockerisation + configuration HuggingFace Spaces

Sprint 1 — Setup initial : arborescence, schémas Pydantic, profils JSON, prompts, tests