* fix(db): default debugMode to false in getSettings() defaults
Fresh installs (or installs missing the persisted debugMode key) ran in
debug mode, contradicting the documented opt-in toggle and flooding new
production installs with debug-level logs. Flip the default to false;
installs that persisted debugMode=true keep it — only the missing-key
path changes, no migration needed.
Fixes#10312
* changelog: fragment for #10372
