build: add zine file watcher to build

build.zig

@@ -339,6 +339,10 @@ pub fn build_exe(
     });
     const syntax_mod = syntax_dep.module("syntax");
 
+    const watcher_mod = b.createModule(.{
+        .root_source_file = b.path("src/watcher/root.zig"),
+    });
+
     const help_mod = b.createModule(.{
         .root_source_file = b.path("help.md"),
     });
@@ -421,6 +425,7 @@ pub fn build_exe(
             .{ .name = "thespian", .module = thespian_mod },
             .{ .name = "vaxis", .module = vaxis_mod },
             .{ .name = "file_type_config", .module = file_type_config_mod },
+            .{ .name = "watcher", .module = watcher_mod },
         },
     });
 

src/watcher/root.zig

@@ -0,0 +1,8 @@
+const builtin = @import("builtin");
+
+pub const Watcher = switch (builtin.target.os.tag) {
+    .linux => @import("serve/watcher/LinuxWatcher.zig"),
+    .macos => @import("serve/watcher/MacosWatcher.zig"),
+    .windows => @import("serve/watcher/WindowsWatcher.zig"),
+    else => @compileError("unsupported platform"),
+};