The admin settings timezone dropdown was incomplete: it had no
pre-selection of the current value, was missing consistent styling,
and the form submission did not persist timezone changes.
Changes:
- frontend.go: load default_timezone from system_settings into the
systemConfig map passed to the template
- admin_settings.templ: match card styling used by the Base URL
section; pre-select current timezone with selected?= attribute
- sidecar.go: handle default_timezone in UpdateSystemConfiguration
by writing to system_settings table instead of system_config;
update HTMX response to include timezone section with current value
- Add selectedAttr() helper for HTMX HTML string response
john-okeefe
ad0bfcac2c