cook: ship the fscrypt stack by default in Phyllome OS

- ingredients/repo/phyllome.ks: add the git.phyllo.me roots registry as a
  downstream repo (install-time only; the phyllome-fscrypt package owns
  /etc/yum.repos.d/phyllome.repo on the installed system)
- ingredients/packages/fscrypt.ks: install phyllome-fscrypt, which pulls
  fscrypt + pam_fscrypt via Requires
- recipe_templates: new 'fscrypt' feature mapping the two fragments
- recipes_manifest: enable fscrypt for phyllomeos and phyllomeos-headless
  (default tier, repository 44)

make lint/validate/test pass; both default dishes regenerate with the
phyllome repo and phyllome-fscrypt included.

cook/ingredients/packages/fscrypt.ks

@@ -0,0 +1,16 @@
+#            __          ____                        ____  _____
+#     ____  / /_  __  __/ / /___  ____ ___  ___     / __ \/ ___/
+#    / __ \/ __ \/ / / / / / __ \/ __ `__ \/ _ \   / / / /\__ \
+#   / /_/ / / / / /_/ / / / /_/ / / / / / /  __/  / /_/ /___/ /
+#  / .___/_/ /_/\__, /_/_/\____/_/ /_/ /_/\___/   \____//____/
+# /_/          /____/
+
+# fscrypt stack: CLI, PAM module and the Phyllome OS configuration package.
+# phyllome-fscrypt depends on fscrypt + pam_fscrypt + authselect, so installing
+# it alone pulls the whole stack.
+
+%packages --exclude-weakdeps
+
+phyllome-fscrypt # SELinux, PAM, repo + first-boot activation for fscrypt
+
+%end # End of the packages section

cook/ingredients/repo/phyllome.ks

@@ -0,0 +1,16 @@
+#            __          ____                        ____  _____
+#     ____  / /_  __  __/ / /___  ____ ___  ___     / __ \/ ___/
+#    / __ \/ __ \/ / / / / / __ \/ __ `__ \/ _ \   / / / /\__ \
+#   / /_/ / / / / /_/ / / / /_/ / / / / / /  __/  / /_/ /___/ /
+#  / .___/_/ /_/\__, /_/_/\____/_/ /_/ /_/\___/   \____//____/
+# /_/          /____/
+
+# Phyllome OS downstream repository: the fscrypt / phyllome-fscrypt RPMs
+# published to the git.phyllo.me roots registry.
+#
+# gpgcheck stays at the anaconda default (enforced by the registry's TLS end-to-
+# end; Gitea's RPM registry does not sign its repodata, see
+# fscrypt-fedora/rpm/README.md). Noverifyssl is not set: the registry presents
+# a valid TLS certificate.
+
+repo --name=phyllome --baseurl=https://git.phyllo.me/api/packages/roots/rpm # Phyllome OS repository (fscrypt stack)