Rebrand to Sri Axis: remove AI + Three.js, rebuild 3D on Babylon.js

Add /debug/env-names to list all env var names for diagnostics

Debug: healthz lists ANTHRO-like env names to diagnose secret naming

Slim Docker build: drop uvicorn[standard], add .dockerignore, use slowapi default handler

Convert to Docker Space: FastAPI /chat proxy with server-side Anthropic key