Lowercase GHCR image repository name in docker builds

[jantman]

Problem

The Docker test build is failing on main after the org transfer:

ERROR: failed to build: invalid tag
"ghcr.io/DecaturMakers/machine-access-control:1b48d748...":
repository name must be lowercase

The DecaturMakers org name has an uppercase letter, but Docker/GHCR repository names must be lowercase. The workflows built image tags directly from ${{ github.repository }}, which carries the uppercase org name.

Fix

Add a step that lowercases $GITHUB_REPOSITORY via bash parameter expansion (${GITHUB_REPOSITORY,,}) and reference its output in the ghcr.io/... tags, in both:

• tests.yml — the docker job (SHA-tagged build)
• release.yml — the publish job (:<tag> and :latest)

The OCI image labels (org.opencontainers.image.url/source) are left as-is since they're GitHub URLs and case-insensitive.

Notes

• No documentation references the GHCR image path explicitly (no docker pull ghcr.io/... in docs/README/compose), so no docs change is needed. The published image will be ghcr.io/decaturmakers/machine-access-control (lowercase).
• This needs to merge before the 0.14.0 tag is pushed, since the release build is triggered by the tag and reads release.yml from the tagged commit.

🤖 Generated with Claude Code

[github-actions]

Coverage Report

File	Stmts	Miss	Branch	BrPart	Cover	Missing
src/dm_mac
__init__.py	73	0	6	0	100%
cli_utils.py	15	0	0	0	100%
neon_fob_adder.py	232	15	60	5	93%	79, 116–117, 124, 270, 333–334, 341, 364–367, 454–456
neongetter.py	211	1	54	3	99%	309
slack_handler.py	220	0	56	0	100%
utils.py	25	0	4	0	100%
src/dm_mac/models
__init__.py	0	0	0	0	100%
api_schemas.py	34	0	0	0	100%
machine.py	592	16	200	16	97%	615, 695, 987–989, 1101–1110, 1168
users.py	103	0	32	0	100%
src/dm_mac/views
__init__.py	0	0	0	0	100%
api.py	32	0	0	0	100%
machine.py	103	0	12	0	100%
prometheus.py	132	0	12	1	100%
TOTAL	1772	32	436	25	98%

Tests	Skipped	Failures	Errors	Time
312	0 💤	0 ❌	0 🔥	24.451s ⏱️

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.