fix(security): remove compromised emSign trust from provider environments - #123

Security repair

The locked certifi2026.7.22 bundle contains the compromised emSign ECC Root CA - G3. GHSA-6q48-6c7w-9gw2 is critical and identifies certifi2026.10.19 as fixed. This affects normal provider HTTPS trust, not the successor price-table implementation.

• Add a runtime floor certifi>=2026.10.19 so fresh installations cannot select the vulnerable bundle.
• Regenerate uv.lock through uv, upgrading only certifi's package version. The resolver also normalizes existing platform markers; other package versions are unchanged.
• Exercise a real default provider HTTP client with certificate verification and hostname checks enabled. Inspect the actual packaged CA certificates by DER fingerprint: retain ISRG Root X1 and reject the compromised emSign G3. No live endpoint, credentials, optional crypto dependency, system-CA assumptions, or disabled TLS verification.

Evidence

• Baseline728b84c: canonical full locked-environment pip-audit exits1, identifying certifi2026.7.22 / GHSA-6q48-6c7w-9gw2.
• The actual default provider TLS regression fails with the old bundle. An isolated installation with the old certifi and an existing Data artifact also fails the fingerprint regression; the provider-session implementation is unchanged from the baseline.
• Patched environment: provider TLS, registry and consistency tests27passed with ResourceWarning treated as errors. Full locked-environment pip-audit exits0: no known vulnerabilities.
• Lock consistency, lint, format and type checks pass. Applicable full hosted source, platform, security, documentation and installed-package checks must pass on this head before ordinary merge.

The regression identities come from the advisory-named certificate in the vulnerable published bundle, not a version comparison or an expected value generated from the repaired input.

Reference: GHSA-6q48-6c7w-9gw2

AI assistance was used for the focused dependency repair and regression. The lock diff, independent root identities and failing-base/passing-fix evidence were reviewed. No release, deployment, insecure fallback or credential action.