Add HERMES_JOURNAL_MODE env / database.journal_mode config for
virtiofs/NFS/SMB where WAL is not crash-safe. Route 5 bypass openers
through apply_wal_with_fallback so a single setting covers every .db
(#68545).
On vulnerable SQLite (e.g. 3.50.4), do not enable WAL for fresh/non-WAL
shared databases — prefer DELETE instead. Leave existing on-disk WAL
alone (no live downgrade under concurrent gateway/cron openers). Surface
Python/SQLite version details as a doctor warning (#69784).