090 template variant passthrough

// Test: `|template(once)|zig` proc variant — template pass renders body via
// Liquid, then strips the `template` tag, leaving `|zig` for normal
// emission. This test uses no template syntax in the body, so the
// rendered output is identical to the input — proves the pipeline runs
// (template tag consumed) without changing the program.

~import std/io

const std = @import("std");

~pub event greet { who: []const u8 }

~proc greet|template(once)|zig {
    std.debug.print("Hello, ", .{});
    std.debug.print("{s}!\n", .{who});
}

~greet(who: "world")