mod: bump zterm dependency; add zlog dependency

`zlog` is used to log messages to the log file that is also used by
`serve` by default, making it a single source for all the log messages.

src/main.zig

@@ -118,10 +118,12 @@ pub fn main() !void {
 }
 
 pub const panic = App.panic_handler;
+pub const std_options = zlog.std_options;
 const log = std.log.scoped(.default);
 
 const std = @import("std");
 const assert = std.debug.assert;
+const zlog = @import("zlog");
 const zterm = @import("zterm");
 const App = zterm.App(
     Model,