Gate PR coverage with diff-cover

[tescalada]

Replaces the per-file coverage baseline with diff-cover, which fails a PR when its changed lines fall below a coverage threshold.

• scripts/run_coverage.sh: builds the test image, runs the suite, and runs diff-cover against the compare branch (origin/main, --fail-under 90; both overridable via env).
• CI installs uv and runs that script.
• Adds the SETUPTOOLS_SCM_PRETEND_VERSION build arg so the test image builds from a git worktree.

[github-actions]

Coverage report

File	Stmts	Miss	Cover	Missing
sparkmeter
__version__.py	16	2	88%	32, 38
_wsgi_mount_smoketest.py	97	97	0%	19–152
app.py	315	11	97%	19–20, 111, 368–375, 552–554, 675, 682–683
asgi.py	74	74	0%	19–166
cli.py	42	6	86%	59–70
cli_app.py	8	8	0%	4–20
cli_prompts.py	15	12	20%	8–12, 17–21, 26–28
conftest.py	181	9	95%	51–52, 85–86, 108–120, 209
controller.py	244	42	83%	183, 207–208, 531, 585–642
debug_memory.py	32	32	0%	6–63
periodic.py	56	31	45%	60–66, 71–75, 80–84, 93–98, 103–111, 124–128
sentry_proxy.py	34	22	35%	38, 44–47, 56–65, 73–82
servercommand.py	112	72	36%	47, 56–60, 64–69, 73–78, 82–85, 89–90, 101–103, 112–181
sparkmeter/alembic/versions
0.32_merge_sms_tables.py	46	3	93%	61–67
0.77_snapshot_support.py	128	2	98%	340, 401
sparkmeter/api
customerviews0.py	283	1	99%	301
historyviews0.py	114	92	19%	49–55, 69–72, 81–131, 144–175, 185–216, 230–257
sparkmeter/config
configparameter.py	57	2	96%	80, 111
sparkmeter/database
alchemy.py	54	4	93%	61–63, 74
database.py	232	3	99%	497, 579–580
ormobject.py	55	1	98%	65
session.py	21	21	0%	12–62
types.py	54	3	94%	91–92, 125
sparkmeter/ground
groundcommand.py	20	10	50%	20–35
sparkmeter/history
historyview.py	35	16	54%	30–31, 41–54, 65–72
sparkmeter/meter
meterdomain.py	772	27	97%	892, 1805–1806, 1817–1868, 1911
sparkmeter/metering
api.py	27	9	67%	66–76
cli.py	227	58	74%	158, 174–175, 184, 193, 198–201, 203, 234, 238–244, 281–297, 301–335, 456–458
dispatch.py	74	16	78%	78–80, 85–97, 185
events.py	105	34	68%	56, 75–77, 109–112, 118–193, 240
lifespan.py	74	74	0%	13–133
reconcile.py	113	43	62%	84–107, 119–120, 129, 135–138, 140–143, 169, 259–262, 266–269, 273–276, 287
sparkmeter/metering/tools
cli_client.py	82	58	29%	46–52, 56–61, 65–70, 83–107, 115–148, 153–166
sparkmeter/misc
datetimeutils.py	65	3	95%	115–117
sparkmeter/system
systemcommand.py	67	5	93%	35, 130–132, 134–135
sparkmeter/tariff
tariffcommand.py	82	15	82%	27–44
sparkmeter/transaction
transactionview.py	167	1	99%	71
sparkmeter/user
userdomain.py	187	12	94%	416–434
sparkmeter/web
unittestutils.py	174	11	94%	30–38, 269, 278, 344, 346
views.py	72	1	99%	71
TOTAL	12652	943	93%

Tests	Skipped	Failures	Errors	Time
1266	0 💤	0 ❌	0 🔥	3m 49s ⏱️

[github-actions]

Diff Coverage

Diff: origin/main...HEAD, staged and unstaged changes

No lines with coverage information in this diff.