History chart: recordHistory() threw away the previous point whenever a
new reading landed within the 2-min de-dup window, but the foreground loop
refreshes every 30s — so history could never grow past one point while the
app was open and the chart stayed stuck on 'Collecting history…'. Now it
throttles by SKIPPING a too-soon reading instead of replacing the last one,
so points accumulate during normal use.
Security:
- Remove hardcoded release keystore passwords from build.gradle.kts; read
from env vars / gitignored keystore.properties; CI injects from Gitea
secrets (KEYSTORE_PASSWORD/KEY_PASSWORD). Signing identity unchanged.
- Make the cookie-never-plaintext invariant explicit on the read path.
- Drop custom ACTION_REFRESH from the exported widget intent-filter so other
apps can't trigger refreshes; internal explicit PendingIntent still works.
- Gate an unguarded Log.w behind BuildConfig.DEBUG.
