v2026.08.13.19 – v2026.08.13.20 — 2026-08-13

• fix(release): use NEW_VERSION (not undefined VERSION) in the checksum-publish step
• chore(changelog): regenerate testing index
• release(supply-chain): publish signed SHA256SUMS to get.enconf.com/checksums (G10)
• build(supply-chain): resolve RELEASE_SIGN_KEY from packaging/.release-sign-key fallback
• chore(changelog): regenerate testing index
• docs: 'Verifying releases' guide (G10 — import key, verify signed SHA256SUMS, reproduce)