rosenthal: Add guile-toml.

* modules/rosenthal/packages/patches/guile-toml-support-boolean.patch: New file.
* modules/rosenthal/packages/guile-xyz.scm (guile-toml): New variable.

modules/rosenthal/packages/guile-xyz.scm

@@ -0,0 +1,47 @@
+;;; SPDX-License-Identifier: GPL-3.0-or-later
+;;; Copyright © 2026 Hilton Chain <hako@ultrarare.space>
+
+(define-module (rosenthal packages guile-xyz)
+  ;; Utilities
+  #:use-module (guix gexp)
+  #:use-module ((guix licenses) #:prefix license:)
+  #:use-module (guix packages)
+  #:use-module (rosenthal utils packages)
+  ;; Guix origin methods
+  #:use-module (guix git-download)
+  ;; Guix build systems
+  #:use-module (guix build-system guile)
+  ;; Guix packages
+  #:use-module (gnu packages guile)
+  #:use-module (gnu packages guile-xyz))
+
+(define-public guile-toml
+  (let ((commit "ecb24deb407ef76ef7cf7e9f0115060c98366a6b")
+        (revision "0"))
+    (package
+      (name "guile-toml")
+      (version (git-version "0.0.0" revision commit))
+      (source (origin
+                (method git-fetch)
+                (uri (git-reference
+                       (url "https://github.com/hylophile/guile-toml")
+                       (commit commit)))
+                (file-name (git-file-name name version))
+                (sha256
+                 (base32
+                  "1iqxivxcb0dcjbd5ba3c0g3mj71b32qjxfdmljyv9r297yykfd02"))
+                (patches
+                 (rosenthal-patches "guile-toml-support-boolean.patch"))))
+      (build-system guile-build-system)
+      (arguments
+       (list #:phases
+             #~(modify-phases %standard-phases
+                 (add-after 'unpack 'avoid-test-installation
+                   (lambda _
+                     (delete-file-recursively "test"))))))
+      (native-inputs (list guile-3.0))
+      (propagated-inputs (list guile-json-4))
+      (home-page "https://github.com/hylophile/guile-toml")
+      (synopsis "TOML module for GNU Guile")
+      (description "")
+      (license license:gpl3+))))

modules/rosenthal/packages/patches/guile-toml-support-boolean.patch

@@ -0,0 +1,37 @@
+From 2f7e3c6f46233f9c9159fac61ca4121fe342107f Mon Sep 17 00:00:00 2001
+From: Hilton Chain <hako@ultrarare.space>
+Date: Thu, 26 Feb 2026 09:57:51 +0800
+Subject: [PATCH] builder: Support boolean value.
+
+* toml/builder.scm (toml-build-boolean): New procedure.
+(toml-build-value): Use it.
+---
+ toml/builder.scm | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/toml/builder.scm b/toml/builder.scm
+index f6bdcea..3531c6f 100644
+--- a/toml/builder.scm
++++ b/toml/builder.scm
+@@ -74,6 +74,9 @@
+                                (else (string c))))
+                             (string->list s))))
+ 
++(define (toml-build-boolean b port)
++  (put-string port (if b "true" "false")))
++
+ (define (toml-build-string s port)
+   (define quote-type (if (or
+                           (string-contains s "\\")
+@@ -198,7 +201,7 @@
+        (scm port #:key (newline? #t) (inline? #f))
+      (cond
+       ;; ((eq? scm null) (toml-build-null port))
+-      ;; ((boolean? scm) (toml-build-boolean scm port))
++      ((boolean? scm) (toml-build-boolean scm port))
+       ;; ((symbol? scm) (toml-build-string (symbol->string scm) port))
+ 
+       ;; TODO float (nan, inf)
+-- 
+2.52.0
+