Simplify-pass follow-up on the #66355 salvage:
1. _config_settings runs on EVERY trim attempt (before the cooldown
check) and only reads — swap load_config for load_config_readonly.
Deep-copying the whole config per attempt generates exactly the
allocator garbage this module exists to release. Tests re-seamed.
2. Trim-failure logs demoted warning->debug at all 3 periodic sites
(gateway housekeeping, idle reaper, slash worker): sibling failure
branches in the same loops log at debug, and a persistent failure
(e.g. broken import after a partial update) would otherwise warn
every 60s forever.
3. The frame-inspection test now asserts the expected locals exist
before reading them — a rename in _run_prompt_submit fails the test
loudly instead of vacuously passing on None.
kshitij
3fad8fdc45