diff --git a/.env.in b/.env.in
index f507d4d7..087d8ee7 100644
--- a/.env.in
+++ b/.env.in
@@ -2,6 +2,11 @@
 #
 # SPDX-License-Identifier: MIT
 
+# Make non-default `./docker-compose*.yml` files the default:
+# https://pscheit.medium.com/docker-compose-advanced-configuration-541356d121de#9aa6
+COMPOSE_PATH_SEPARATOR=:
+COMPOSE_FILE=./docker-compose.yml:./gitlab-runner/docker-compose.yml:./docker-compose.override.yml
+
 # Capture local values specific to this checkout:
 TZ=${TZ}
 PUID=${PUID}
diff --git a/.gitignore b/.gitignore
index c130cff1..ff138848 100644
--- a/.gitignore
+++ b/.gitignore
@@ -66,8 +66,8 @@ nosetests.xml
 *,cover
 **/,cover
 .hypothesis
-.mypy_cache
-**/.mypy_cache
+.pytest_cache
+**/.pytest_cache
 
 # Translations
 *.mo
@@ -108,6 +108,7 @@ celerybeat-schedule
 # Linters:
 .tox
 .mypy_cache
+**/.mypy_cache
 
 # virtualenv
 venv
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index e62a7d59..3e0c4ec8 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -15,7 +15,9 @@ variables:
 
 default:
   image:
-    name: "$CI_TEMPLATE_REGISTRY_HOST/$PROJECT_NAMESPACE/$CI_PROJECT_NAME:build-host"
+    # TEMPLATE: Only change these if you customize the `./build-host/Dockerfile` image.
+    # Otherwise use the version of this image from the project template in your CI/CD.
+    name: "registry.gitlab.com/rpatterson/project-structure:build-host"
     entrypoint:
       - "docker-entrypoint.sh"
   services:
diff --git a/Makefile b/Makefile
index 253b80d8..9c926113 100644
--- a/Makefile
+++ b/Makefile
@@ -15,6 +15,8 @@ export PROJECT_NAMESPACE=rpatterson
 export PROJECT_NAME=prunerr
 NPM_SCOPE=rpattersonnet
 export DOCKER_USER=merpatterson
+# TEMPLATE: See comments towards the bottom and update.
+GPG_SIGNING_KEYID=2EFF7CCE6828E359
 
 # Option variables that control behavior:
 export TEMPLATE_IGNORE_EXISTING=false
@@ -130,8 +132,8 @@ ifeq ($(PYTHON_MINOR),)
 # Fallback to the latest installed supported Python version
 PYTHON_MINOR=$(PYTHON_LATEST_BASENAME:python%=%)
 endif
-PYTHON_LATEST_MINOR=$(firstword $(PYTHON_SUPPORTED_MINORS))
-PYTHON_LATEST_ENV=py$(subst .,,$(PYTHON_LATEST_MINOR))
+PYTHON_DEFAULT_MINOR=$(firstword $(PYTHON_SUPPORTED_MINORS))
+PYTHON_DEFAULT_ENV=py$(subst .,,$(PYTHON_DEFAULT_MINOR))
 PYTHON_MINORS=$(PYTHON_SUPPORTED_MINORS)
 ifeq ($(PYTHON_MINOR),)
 PYTHON_MINOR=$(firstword $(PYTHON_MINORS))
@@ -272,7 +274,7 @@ export TOX_RUN_ARGS
 # The options that support running arbitrary commands in the venvs managed by tox
 # without Tox's startup time:
 TOX_EXEC_OPTS=--no-recreate-pkg --skip-pkg-install
-TOX_EXEC_ARGS=tox exec $(TOX_EXEC_OPTS) -e "$(PYTHON_ENV)"
+TOX_EXEC_ARGS=tox exec $(TOX_EXEC_OPTS) -e "$(PYTHON_DEFAULT_ENV)"
 TOX_EXEC_BUILD_ARGS=tox exec $(TOX_EXEC_OPTS) -e "build"
 PIP_COMPILE_EXTRA=
 
@@ -386,9 +388,9 @@ ifeq ($(CI),true)
 export PIP_COMPILE_ARGS=
 endif
 GITHUB_RELEASE_ARGS=--prerelease
+DOCKER_PLATFORMS=
 # Only publish releases from the `main` or `develop` branches and only under the
 # canonical CI/CD platform:
-DOCKER_PLATFORMS=
 ifeq ($(GITLAB_CI),true)
 ifeq ($(VCS_BRANCH),main)
 RELEASE_PUBLISH=true
@@ -1041,7 +1043,9 @@ endif
 ## Automatically correct code in this checkout according to linters and style checkers.
 devel-format: $(HOST_TARGET_DOCKER) ./var/log/npm-install.log $(HOME)/.local/bin/tox
 # Add license and copyright header to files missing them:
-	git ls-files -co --exclude-standard -z ':!*.license' ':!.reuse' ':!LICENSES' |
+	git ls-files -co --exclude-standard -z ':!*.license' ':!.reuse' ':!LICENSES' \
+	    ':!newsfragments/*' ':!NEWS*.rst' ':!styles/*/meta.json' \
+	    ':!styles/*/*.yml' ':!requirements/*/*.txt' |
 	while read -d $$'\0'
 	do
 	    if ! (
diff --git a/bin/test-lint-docs.sh b/bin/test-lint-docs.sh
index 869bee93..33f63748 100755
--- a/bin/test-lint-docs.sh
+++ b/bin/test-lint-docs.sh
@@ -8,7 +8,7 @@
 
 set -eu -o pipefail
 shopt -s inherit_errexit
-if [ "${DEBUG:=false}" = "true" ]
+if test "${DEBUG:=false}" = "true"
 then
     # Echo commands for easier debugging
     set -x
diff --git a/bin/test-lint-prose.sh b/bin/test-lint-prose.sh
index 30882858..08c12c8a 100755
--- a/bin/test-lint-prose.sh
+++ b/bin/test-lint-prose.sh
@@ -8,7 +8,7 @@
 
 set -eu -o pipefail
 shopt -s inherit_errexit
-if [ "${DEBUG:=false}" = "true" ]
+if test "${DEBUG:=false}" = "true"
 then
     # Echo commands for easier debugging
     set -x
diff --git a/build-host/Dockerfile b/build-host/Dockerfile
index a5b1edee..30098e15 100644
--- a/build-host/Dockerfile
+++ b/build-host/Dockerfile
@@ -28,9 +28,9 @@ LABEL org.opencontainers.image.base.name="docker.io/library/docker:latest"
 # Build-time labels:
 LABEL org.opencontainers.image.version=1.0.0
 
-# Find the same home directory even when run as another user, for example `root`:
 ENV PROJECT_NAMESPACE="${PROJECT_NAMESPACE}"
 ENV PROJECT_NAME="${PROJECT_NAME}"
+# Find the same home directory even when run as another user, for example `root`:
 ENV HOME="/home/runner"
 ENV PATH="${HOME}/.local/bin:${PATH}"
 # Prevent Node Version Manager (NVM) installing into `/bin/versions/**`:
diff --git a/docker-compose.override.yml b/docker-compose.override.yml
index a4c92601..07a005ff 100644
--- a/docker-compose.override.yml
+++ b/docker-compose.override.yml
@@ -22,7 +22,7 @@ services:
   # Configuration specific to development:
   prunerr-daemon:
     image: "\
-      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/prunerr\
+      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/rpatterson\
       /prunerr:${PYTHON_ENV:-py311}-${DOCKER_BRANCH_TAG:-develop}"
     container_name: "prunerr-daemon-checkout"
     build:
@@ -38,7 +38,7 @@ services:
   # Container for use by developers:
   prunerr-devel:
     image: "\
-      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/prunerr\
+      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/rpatterson\
       /prunerr:devel-${PYTHON_ENV:-py311}-${DOCKER_BRANCH_TAG:-develop}"
     container_name: "prunerr-devel"
     profiles:
@@ -164,7 +164,7 @@ services:
   # The container that runs CI/CD:
   build-host:
     image: "\
-      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/${DOCKER_USER:-}/prunerr\
+      ${DOCKER_REGISTRY_HOST:-registry.gitlab.com}/rpatterson/prunerr\
       :build-host"
     profiles:
       - "ci"
diff --git a/docs/conf.py b/docs/conf.py
index c47df287..a1460182 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -36,3 +36,9 @@
 # Linter options:
 # Disallow redirects:
 linkcheck_allowed_redirects = {}
+linkcheck_anchors_ignore = [
+    # The default from the Sphinx extension:
+    "^!",
+    # Tolerate links to source code lines in VCS provider web UIs:
+    "^L[0-9]+",
+]
diff --git a/newsfragments/+upgrade-requirements.bugfix.rst b/newsfragments/+upgrade-requirements.bugfix.rst
index 5c603a01..1c5600dc 100644
--- a/newsfragments/+upgrade-requirements.bugfix.rst
+++ b/newsfragments/+upgrade-requirements.bugfix.rst
@@ -1,2 +1,2 @@
 Upgrade all requirements to the most recent versions as of
-Thu Oct 26 11:56:03 AM UTC 2023.
+Sun Oct 29 03:13:29 PM UTC 2023.
diff --git a/requirements/py310/build.txt b/requirements/py310/build.txt
index 69b2c102..d10970fa 100644
--- a/requirements/py310/build.txt
+++ b/requirements/py310/build.txt
@@ -51,11 +51,11 @@ docutils==0.20.1
     #   restructuredtext-lint
     #   rstcheck-core
     #   sphinx
-filelock==3.12.4
+filelock==3.13.0
     # via virtualenv
 future==0.18.3
     # via proselint
-identify==2.5.30
+identify==2.5.31
     # via pre-commit
 idna==3.4
     # via requests
diff --git a/requirements/py311/build.txt b/requirements/py311/build.txt
index baa6f3c6..54ab9a95 100644
--- a/requirements/py311/build.txt
+++ b/requirements/py311/build.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.11
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py311/build.txt --resolver=backtracking --strip-extras requirements/build.txt.in
+#    pip-compile --output-file=requirements/py311/build.txt --strip-extras requirements/build.txt.in
 #
 alabaster==0.7.13
     # via sphinx
@@ -51,11 +51,11 @@ docutils==0.20.1
     #   restructuredtext-lint
     #   rstcheck-core
     #   sphinx
-filelock==3.12.4
+filelock==3.13.0
     # via virtualenv
 future==0.18.3
     # via proselint
-identify==2.5.30
+identify==2.5.31
     # via pre-commit
 idna==3.4
     # via requests
@@ -201,7 +201,9 @@ towncrier==23.10.0
 twine==4.0.2
     # via -r requirements/build.txt.in
 typer==0.9.0
-    # via rstcheck
+    # via
+    #   rstcheck
+    #   typer
 typing-extensions==4.8.0
     # via
     #   pydantic
diff --git a/requirements/py311/devel.txt b/requirements/py311/devel.txt
index d5fc998d..73016654 100644
--- a/requirements/py311/devel.txt
+++ b/requirements/py311/devel.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.11
 # by the following command:
 #
-#    pip-compile --extra=devel --output-file=requirements/py311/devel.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=devel --output-file=requirements/py311/devel.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py311/test.txt b/requirements/py311/test.txt
index 4f85bfdd..c68de5c7 100644
--- a/requirements/py311/test.txt
+++ b/requirements/py311/test.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.11
 # by the following command:
 #
-#    pip-compile --extra=test --output-file=requirements/py311/test.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=test --output-file=requirements/py311/test.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py311/user.txt b/requirements/py311/user.txt
index b8a608f2..13d20d9f 100644
--- a/requirements/py311/user.txt
+++ b/requirements/py311/user.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.11
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py311/user.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --output-file=requirements/py311/user.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py312/build.txt b/requirements/py312/build.txt
index b3a68836..186ed57a 100644
--- a/requirements/py312/build.txt
+++ b/requirements/py312/build.txt
@@ -51,11 +51,11 @@ docutils==0.20.1
     #   restructuredtext-lint
     #   rstcheck-core
     #   sphinx
-filelock==3.12.4
+filelock==3.13.0
     # via virtualenv
 future==0.18.3
     # via proselint
-identify==2.5.30
+identify==2.5.31
     # via pre-commit
 idna==3.4
     # via requests
diff --git a/requirements/py38/build.txt b/requirements/py38/build.txt
index 6c0ff0bf..e6c83380 100644
--- a/requirements/py38/build.txt
+++ b/requirements/py38/build.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.8
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py38/build.txt --resolver=backtracking --strip-extras requirements/build.txt.in
+#    pip-compile --output-file=requirements/py38/build.txt --strip-extras requirements/build.txt.in
 #
 alabaster==0.7.13
     # via sphinx
@@ -51,11 +51,11 @@ docutils==0.20.1
     #   restructuredtext-lint
     #   rstcheck-core
     #   sphinx
-filelock==3.12.4
+filelock==3.13.0
     # via virtualenv
 future==0.18.3
     # via proselint
-identify==2.5.30
+identify==2.5.31
     # via pre-commit
 idna==3.4
     # via requests
@@ -209,7 +209,9 @@ towncrier==23.10.0
 twine==4.0.2
     # via -r requirements/build.txt.in
 typer==0.9.0
-    # via rstcheck
+    # via
+    #   rstcheck
+    #   typer
 typing-extensions==4.8.0
     # via
     #   annotated-types
diff --git a/requirements/py38/devel.txt b/requirements/py38/devel.txt
index 5a9d77a4..c972523a 100644
--- a/requirements/py38/devel.txt
+++ b/requirements/py38/devel.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.8
 # by the following command:
 #
-#    pip-compile --extra=devel --output-file=requirements/py38/devel.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=devel --output-file=requirements/py38/devel.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py38/test.txt b/requirements/py38/test.txt
index 4c41a44b..2bc0dd54 100644
--- a/requirements/py38/test.txt
+++ b/requirements/py38/test.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.8
 # by the following command:
 #
-#    pip-compile --extra=test --output-file=requirements/py38/test.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=test --output-file=requirements/py38/test.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py38/user.txt b/requirements/py38/user.txt
index 107ace13..e31442a0 100644
--- a/requirements/py38/user.txt
+++ b/requirements/py38/user.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.8
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py38/user.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --output-file=requirements/py38/user.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py39/build.txt b/requirements/py39/build.txt
index 8c277549..287959fb 100644
--- a/requirements/py39/build.txt
+++ b/requirements/py39/build.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.9
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py39/build.txt --resolver=backtracking --strip-extras requirements/build.txt.in
+#    pip-compile --output-file=requirements/py39/build.txt --strip-extras requirements/build.txt.in
 #
 alabaster==0.7.13
     # via sphinx
@@ -51,11 +51,11 @@ docutils==0.20.1
     #   restructuredtext-lint
     #   rstcheck-core
     #   sphinx
-filelock==3.12.4
+filelock==3.13.0
     # via virtualenv
 future==0.18.3
     # via proselint
-identify==2.5.30
+identify==2.5.31
     # via pre-commit
 idna==3.4
     # via requests
@@ -208,7 +208,9 @@ towncrier==23.10.0
 twine==4.0.2
     # via -r requirements/build.txt.in
 typer==0.9.0
-    # via rstcheck
+    # via
+    #   rstcheck
+    #   typer
 typing-extensions==4.8.0
     # via
     #   pydantic
diff --git a/requirements/py39/devel.txt b/requirements/py39/devel.txt
index 6452870a..91fcd5b4 100644
--- a/requirements/py39/devel.txt
+++ b/requirements/py39/devel.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.9
 # by the following command:
 #
-#    pip-compile --extra=devel --output-file=requirements/py39/devel.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=devel --output-file=requirements/py39/devel.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py39/test.txt b/requirements/py39/test.txt
index abceff53..39198732 100644
--- a/requirements/py39/test.txt
+++ b/requirements/py39/test.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.9
 # by the following command:
 #
-#    pip-compile --extra=test --output-file=requirements/py39/test.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --extra=test --output-file=requirements/py39/test.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)
diff --git a/requirements/py39/user.txt b/requirements/py39/user.txt
index a4ce3b75..cfc7155e 100644
--- a/requirements/py39/user.txt
+++ b/requirements/py39/user.txt
@@ -2,7 +2,7 @@
 # This file is autogenerated by pip-compile with Python 3.9
 # by the following command:
 #
-#    pip-compile --output-file=requirements/py39/user.txt --resolver=backtracking --strip-extras pyproject.toml
+#    pip-compile --output-file=requirements/py39/user.txt --strip-extras pyproject.toml
 #
 argcomplete==3.1.2
     # via prunerr (pyproject.toml)