Initial backup of LTP-305G matrix clock setup on matrixpi

Captures everything needed to redeploy the two-display clock (hour on I2C
0x61, minute on I2C 0x63) on a fresh Pi:

- Both systemd units (matrix0x61.service, matrix0x63.service)
- Deployed Pimoroni script tree, including the local %I (12-hour) clock
  customization
- Vendored upstream sources (ltp305-python, breakout-garden) so restore is
  fully offline-capable
- Boot config snippet enabling I2C
- install.sh that wires it all back up idempotently
- Inventory doc cross-referencing every live-system path

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

vendor/ltp305-python/Makefile

@@ -0,0 +1,70 @@
+LIBRARY_VERSION=$(shell grep version library/setup.cfg | awk -F" = " '{print $$2}')
+LIBRARY_NAME=$(shell grep name library/setup.cfg | awk -F" = " '{print $$2}')
+
+.PHONY: usage install uninstall
+usage:
+	@echo "Library: ${LIBRARY_NAME}"
+	@echo "Version: ${LIBRARY_VERSION}\n"
+	@echo "Usage: make <target>, where target is one of:\n"
+	@echo "install:       install the library locally from source"
+	@echo "uninstall:     uninstall the local library"
+	@echo "check:         peform basic integrity checks on the codebase"
+	@echo "python-readme: generate library/README.md from README.md + library/CHANGELOG.txt"
+	@echo "python-wheels: build python .whl files for distribution"
+	@echo "python-sdist:  build python source distribution"
+	@echo "python-clean:  clean python build and dist directories"
+	@echo "python-dist:   build all python distribution files"
+	@echo "python-testdeploy: build all and deploy to test PyPi"
+	@echo "tag:           tag the repository with the current version"
+
+install:
+	./install.sh
+
+uninstall:
+	./uninstall.sh
+
+check:
+	@echo "Checking for trailing whitespace"
+	@! grep -IUrn --color "[[:blank:]]$$" --exclude-dir=sphinx --exclude-dir=.tox --exclude-dir=.git --exclude=PKG-INFO
+	@echo "Checking for DOS line-endings"
+	@! grep -IUrn --color "
+" --exclude-dir=sphinx --exclude-dir=.tox --exclude-dir=.git --exclude=Makefile
+	@echo "Checking library/CHANGELOG.txt"
+	@cat library/CHANGELOG.txt | grep ^${LIBRARY_VERSION}
+	@echo "Checking library/${LIBRARY_NAME}/__init__.py"
+	@cat library/${LIBRARY_NAME}/__init__.py | grep "^__version__ = '${LIBRARY_VERSION}'"
+
+tag:
+	git tag -a "v${LIBRARY_VERSION}" -m "Version ${LIBRARY_VERSION}"
+
+python-readme: library/README.md
+
+python-license: library/LICENSE.txt
+
+library/README.md: README.md library/CHANGELOG.txt
+	cp README.md library/README.md
+	printf "\n# Changelog\n" >> library/README.md
+	cat library/CHANGELOG.txt >> library/README.md
+
+library/LICENSE.txt: LICENSE
+	cp LICENSE library/LICENSE.txt
+
+python-wheels: python-readme python-license
+	cd library; python3 setup.py bdist_wheel
+	cd library; python setup.py bdist_wheel
+
+python-sdist: python-readme python-license
+	cd library; python setup.py sdist
+
+python-clean:
+	-rm -r library/dist
+	-rm -r library/build
+	-rm -r library/*.egg-info
+
+python-dist: python-clean python-wheels python-sdist
+	ls library/dist
+
+python-testdeploy: python-dist
+	twine upload --repository-url https://test.pypi.org/legacy/ library/dist/*
+
+python-deploy: check python-dist