fix(peeks,scripts): use per-key settings storage matching schema
The peeks and scripts feature backgrounds called api.settings.get/set('data')
to load a single combined object, but the actual datastore writes — and the
features' settings-schema.json files — use separate top-level keys per field
('prefs'+'items' for peeks, 'scripts' for scripts).
Result: loadSettings() always missed the user's saved data and fell back to
defaults. For peeks specifically this meant only the default Option+0 shortcut
was registered, ignoring the user's configured shortcuts in the prod profile.
Refactor loadSettings/saveSettings in both features to read/write the per-key
shape that matches the schema.