_SLASH_WORKER_TIMEOUT_S and _pool used raw float()/int() on env vars
at module level. A non-numeric value (e.g. HERMES_TUI_SLASH_TIMEOUT_S=abc)
raises ValueError during import, preventing TUI gateway from starting
with no useful error message.
Wrap both parses in try/except with safe fallbacks:
- HERMES_TUI_SLASH_TIMEOUT_S: fallback to 45.0s
- HERMES_TUI_RPC_POOL_WORKERS: fallback to 4 workers