Restructure modules with per-module addon subdirs

- Each module (outline, interact, screenshot) now has its own addon/
  subdir with .toc, .lua, and Bindings.xml
- Core WeirdUtils addon lives in src/core/addon/
- build.zig supports compile-time feature gating via -D options
- main.zig uses build_options for conditional imports and addon embedding
- Module addons only load when their module is compiled in
- 'zig build all-variants' produces full.dll + 3 single-module DLLs

build.zig

@@ -8,6 +8,18 @@ pub fn build(b: *std.Build) void {
     });
     const optimize = b.standardOptimizeOption(.{});
 
+    // Build options for conditional module compilation
+    const enable_screenshot = b.option(bool, "screenshot", "Enable screenshot module") orelse true;
+    const enable_interact = b.option(bool, "interact", "Enable interact module") orelse true;
+    const enable_outline = b.option(bool, "outline", "Enable outline module") orelse true;
+
+    // Create build options module
+    const build_options = b.addOptions();
+    build_options.addOption(bool, "enable_screenshot", enable_screenshot);
+    build_options.addOption(bool, "enable_interact", enable_interact);
+    build_options.addOption(bool, "enable_outline", enable_outline);
+    const build_options_module = build_options.createModule();
+
     const hook_mod = b.dependency("hook", .{
         .target = target,
         .optimize = optimize,
@@ -22,9 +34,45 @@ pub fn build(b: *std.Build) void {
             .optimize = optimize,
             .imports = &.{
                 .{ .name = "hook", .module = hook_mod },
+                .{ .name = "build_options", .module = build_options_module },
             },
         }),
     });
 
     b.installArtifact(lib);
+
+    // Convenience step to build all single-module variants
+    const build_all_step = b.step("all-variants", "Build all DLL variants");
+
+    // Helper to create a single-module build
+    inline for (&[_]struct { name: []const u8, screenshot: bool, interact: bool, outline: bool }{
+        .{ .name = "full", .screenshot = true, .interact = true, .outline = true },
+        .{ .name = "screenshot", .screenshot = true, .interact = false, .outline = false },
+        .{ .name = "interact", .screenshot = false, .interact = true, .outline = false },
+        .{ .name = "outline", .screenshot = false, .interact = false, .outline = true },
+    }) |variant| {
+        const opts = b.addOptions();
+        opts.addOption(bool, "enable_screenshot", variant.screenshot);
+        opts.addOption(bool, "enable_interact", variant.interact);
+        opts.addOption(bool, "enable_outline", variant.outline);
+
+        const variant_lib = b.addLibrary(.{
+            .name = variant.name,
+            .linkage = .dynamic,
+            .root_module = b.createModule(.{
+                .root_source_file = b.path("src/main.zig"),
+                .target = target,
+                .optimize = optimize,
+                .imports = &.{
+                    .{ .name = "hook", .module = hook_mod },
+                    .{ .name = "build_options", .module = opts.createModule() },
+                },
+            }),
+        });
+
+        const install_variant = b.addInstallArtifact(variant_lib, .{
+            .dest_dir = .{ .override = .{ .custom = "variants" } },
+        });
+        build_all_step.dependOn(&install_variant.step);
+    }
 }