milestone 20: declarative configuration for iac

src/storage/repositories/settings_repo.zig

@@ -88,6 +88,18 @@ pub fn putSetting(database: *db.Db, key: []const u8, value: []const u8) db.Error
     try stmt.exec();
 }
 
+/// Removes one key. Silent about a key that is not stored: the reconcile
+/// engine's sweep computes the set of keys to drop from a list it has already
+/// read, so "no such row" is not a caller error the way it is for a by-id
+/// mutation, and `execStrict` would turn a harmless race into a failed
+/// transaction.
+pub fn deleteSetting(database: *db.Db, key: []const u8) db.Error!void {
+    var stmt = try database.prepare("DELETE FROM settings WHERE key = ?1");
+    defer stmt.deinit();
+    try stmt.bindText(1, key);
+    return stmt.exec();
+}
+
 // ---------------------------------------------------------------------------
 // tests
 // ---------------------------------------------------------------------------