Splits heavy deps (torch, vllm, faiss-cpu, gradio, plotly, llmlingua) from
main dependencies into a new [serve] optional extra. The slim install
() now pulls only the JCR safety kernel
+ z3 certifier + pydantic + fastapi, with NO torch/vllm/faiss/gradio.

This unblocks the apohara-probanza monorepo from inheriting the
gradio<5.24 / pydantic<=2.12.3 chain (which transitively blocked the
pydantic 2.13 + starlette 1.0.1 [CVE-2026-48710 BadHost] upgrades).

Install patterns:
  pip install apohara-context-forge            # slim (JCR + z3)
  pip install apohara-context-forge[serve]     # full stack (torch, vllm, etc.)

Merged via: pull request #41 (SuarezPM/slim-safety-split)
Migration notes: docs/upstream/context-forge-slim-pr.md in apohara-probanza