Implement some simple flags and runtime log-levels

I used flags.zig from Isaac Freund for parsing basic CLI arguments,
I don't need much else since most configuration is in Kdl.
e967499fb1/common/flags.zig

I also removed some of the duplicated bits for the exe_check step
since I realized I can just use the beansprout executable for all of it.

build.zig

@@ -36,7 +36,10 @@ pub fn build(b: *std.Build) void {
     scanner.generate("river_layer_shell_v1", 1);
     scanner.generate("zwlr_layer_shell_v1", 3);
 
-    const exe = b.addExecutable(.{
+    const options = b.addOptions();
+    options.addOption([]const u8, "version", version);
+
+    const beansprout = b.addExecutable(.{
         .name = "beansprout",
         .root_module = b.createModule(.{
             .root_source_file = b.path("src/main.zig"),
@@ -45,42 +48,26 @@ pub fn build(b: *std.Build) void {
             .strip = strip,
         }),
     });
-    exe.pie = pie;
+    beansprout.pie = pie;
 
-    // Make sure to also add new imports to the exe_check step
-    exe.root_module.addImport("wayland", wayland);
-    exe.root_module.addImport("kdl", kdl);
-    exe.root_module.addImport("known_folders", known_folders);
-    exe.root_module.addImport("pixman", pixman);
-    exe.root_module.addImport("xkbcommon", xkbcommon);
-    exe.root_module.addImport("zigimg", zigimg);
+    beansprout.root_module.addOptions("build_options", options);
 
-    exe.linkLibC();
-    exe.linkSystemLibrary("wayland-client");
-    exe.linkSystemLibrary("pixman-1");
-    exe.linkSystemLibrary("xkbcommon");
+    beansprout.root_module.addImport("wayland", wayland);
+    beansprout.root_module.addImport("kdl", kdl);
+    beansprout.root_module.addImport("known_folders", known_folders);
+    beansprout.root_module.addImport("pixman", pixman);
+    beansprout.root_module.addImport("xkbcommon", xkbcommon);
+    beansprout.root_module.addImport("zigimg", zigimg);
 
-    b.installArtifact(exe);
+    beansprout.linkLibC();
+    beansprout.linkSystemLibrary("wayland-client");
+    beansprout.linkSystemLibrary("pixman-1");
+    beansprout.linkSystemLibrary("xkbcommon");
 
-    const run_cmd = b.addRunArtifact(exe);
-
-    // By making the run step depend on the install step, it will be run from the
-    // installation directory rather than directly from within the cache directory.
-    // This is not necessary, however, if the application depends on other installed
-    // files, this ensures they will be present and in the expected location.
-    run_cmd.step.dependOn(b.getInstallStep());
-
-    // This allows the user to pass arguments to the application in the build
-    // command itself, like this: `zig build run -- arg1 arg2 etc`
-    if (b.args) |args| {
-        run_cmd.addArgs(args);
-    }
-
-    const run_step = b.step("run", "Run beansprout");
-    run_step.dependOn(&run_cmd.step);
+    b.installArtifact(beansprout);
 
     const exe_unit_tests = b.addTest(.{
-        .root_module = exe.root_module,
+        .root_module = beansprout.root_module,
     });
 
     const run_exe_unit_tests = b.addRunArtifact(exe_unit_tests);
@@ -88,29 +75,44 @@ pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Run unit tests");
     test_step.dependOn(&run_exe_unit_tests.step);
 
-    // check step used for zls to give comptime info
-    const exe_check = b.addExecutable(.{
-        .name = "beansprout",
-        .root_module = b.createModule(.{
-            .root_source_file = b.path("src/main.zig"),
-            .target = target,
-            .optimize = optimize,
-            .strip = strip,
-        }),
-    });
-
-    exe_check.root_module.addImport("wayland", wayland);
-    exe_check.root_module.addImport("kdl", kdl);
-    exe_check.root_module.addImport("known_folders", known_folders);
-    exe_check.root_module.addImport("pixman", pixman);
-    exe_check.root_module.addImport("xkbcommon", xkbcommon);
-    exe_check.root_module.addImport("zigimg", zigimg);
-
-    exe_check.linkLibC();
-    exe_check.linkSystemLibrary("wayland-client");
-    exe_check.linkSystemLibrary("pixman-1");
-    exe_check.linkSystemLibrary("xkbcommon");
-
+    // Use by zls to get inline compilation errors
     const check = b.step("check", "Check if beansprout compiles");
-    check.dependOn(&exe_check.step);
+    check.dependOn(&beansprout.step);
 }
+
+const version = manifest.version;
+/// Needed until https://github.com/ziglang/zig/issues/22775
+/// is addressed.
+const manifest: struct {
+    name: @Type(.enum_literal),
+    version: []const u8,
+    fingerprint: u64,
+    minimum_zig_version: []const u8,
+    dependencies: struct {
+        wayland: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+        xkbcommon: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+        kdl: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+        known_folders: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+        pixman: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+        zigimg: struct {
+            url: []const u8,
+            hash: []const u8,
+        },
+    },
+    paths: []const []const u8,
+} = @import("build.zig.zon");