home check: home-manager build without switch — homeCheck runs 'home-manager build' (validates + builds, no activation), prints ':: ok' on success or routes to checkFailed + BuildFailed on non-zero; build+tests green

@@ -948,8 +948,19 @@948948 949949     if (std.mem.eql(u8, ctx.sub, "back")) return homeBack(ctx);950950     if (std.mem.eql(u8, ctx.sub, "history")) return homeHistory(ctx);951+    if (std.mem.eql(u8, ctx.sub, "check")) return homeCheck(ctx);951952 952953     return output.subcommandHelp("home", &home_help, null);954+}955+956+fn homeCheck(ctx: Ctx) !void {957+    output.homeCheckStart(ctx.machine.name);958+    const code = try exec.homeManagerBuild(ctx.io, &ctx.machine, ctx.gpa);959+    if (code != 0) {960+        output.checkFailed("");961+        return error.BuildFailed;962+    }963+    output.homeCheckOk();953964 }954965 955966 fn homeEdit(ctx: Ctx) !void {