Draft plan for consolidating pytest CLI flags,
ad-hoc env vars, and hardcoded fixture defaults
into the existing (but unused) `RuntimeVars`
struct as the single source of truth.
Deats,
- `_rtvars.py` leaf mod w/ `dump`/`load`/`get`/
`update` helpers using `str(dict)` +
`ast.literal_eval` encoding
- phased migration: test infra first, then
runtime callers, then per-session bindspace
- addresses concurrent pytest session collisions
and subproc env propagation for `devx/` scripts
(this patch was generated in some part by [`claude-code`][claude-code-gh])
[claude-code-gh]: https://github.com/anthropics/claude-code