stage-362: revert #2323 — Opus caught silent regression in profile routing

CHANGELOG.md

@@ -10,7 +10,6 @@
 
 - **PR #2322** by @Michaelyklam (refs #2271) — LAN Ollama models selected from endpoint-discovered `custom:<host>-<port>` / `custom:<host>:<port>` picker entries now route through the configured `ollama` provider and base URL instead of surfacing a missing `CUSTOM_*_API_KEY` error. The picker still surfaces endpoint-discovered entries; the fix is to recognize them as UI routing hints matching the configured local-server base URL and resolve them via the actual `ollama` provider.
 
-- **PR #2323** by @Michaelyklam (closes #2321) — Background worker profile env isolation refactor: `profile_env_for_background_worker()` now routes profile-specific env through the same `_set_thread_env` thread-local channel used by foreground streaming runs, instead of mutating `os.environ`. Pre-fix, two profile-scoped workers running concurrently could observe or restore each other's temporary process env. The thread-local approach eliminates that cross-profile race entirely. `os.environ` is no longer touched at all in this path; the short `_ENV_LOCK` critical section now only protects the remaining process-global skill-home module cache patch. Implements the long-term architectural fix Opus surfaced during v0.51.67 stage-360 review.
 
 - **PR #2326** by @Michaelyklam (closes #2232) — Legacy `hermes` CLI toolset alias is now normalized to `hermes-cli` + `hermes-api-server` when WebUI resolves CLI toolsets from shared Hermes config. Modern Hermes Agent exposes the composite under those two names; older configs that still contain the legacy `hermes` toolset name no longer surface as "unknown toolset" warnings.