LOG_DEBUG/LOG_UTC docs stale after rename to BASE_BASH_LIBS_LOG_DEBUG/LOG_UTC

[codeforester]

Problem

docs/runtime-environment.md:185-186, docs/cache-ownership-and-layout.md:174-177, and docs/shell-startup.md:181 all document --debug-wrapper as enabling LOG_DEBUG=1 and --utc-wrapper as enabling LOG_UTC=1 (rendering both Bash and Python log streams in UTC).

The actual variables set by these flags are BASE_BASH_LIBS_LOG_DEBUG=1 and BASE_BASH_LIBS_LOG_UTC=1 -- confirmed in bin/basectl:244-255 and cli/bash/commands/basectl/basectl.sh:283. Commit f8d2d2e ("migrate Base consumers to base-bash-libs v2 API", 2026-08-05) renamed these variables; the docs still describe the pre-rename names.

More importantly, this isn't just a naming mismatch -- it's a behavior gap. Bare LOG_DEBUG is only ever read as a fallback (for BASE_CLI_LOG_LEVEL=debug) in cli/python/base_cli_adapters/config.py:254, never set by these flags; bare LOG_UTC is never set anywhere in the repo, and the installed base_cli package's logging.py:193 reads bare LOG_UTC for its own UTC decision. Net effect: --utc-wrapper and --debug-wrapper no longer propagate to Python-backed log rendering the way the docs describe -- since the rename, these flags only affect Bash-side logging, not the Python log stream the docs claim they cover.

docs/runtime-environment.md was itself last edited 2026-08-24, after the rename -- so this is current drift, not a stale-but-already-fixed claim.

Why this matters

A contributor following the docs to get UTC or debug output from the Python log stream via --utc-wrapper/--debug-wrapper would set the flag, see no effect on Python-side logs, and have no reason to suspect the docs are describing renamed variables -- this is exactly the kind of silent behavior gap that's hard to self-diagnose.

Proposed change

Either:

• Update the three docs to the correct variable names (BASE_BASH_LIBS_LOG_DEBUG/BASE_BASH_LIBS_LOG_UTC) and clarify that these flags now only affect Bash-side logging, not the Python log stream; or
• If Python-side propagation was intended to still work after the v2 API migration, treat this as a functional regression to fix in code (wire the flags through to LOG_DEBUG/LOG_UTC or their Python equivalents) rather than just a doc fix.

Acceptance criteria

• The three docs accurately describe which variables --debug-wrapper/--utc-wrapper set and which log streams (Bash-only vs. Bash+Python) are actually affected today.