Add --source, --error-message, --failed-step flags to gstack-telemetry-log.
Source tagging (live vs test via GSTACK_TELEMETRY_SOURCE env) prevents E2E
tests from polluting production data. Duration guards cap unreasonable
values (>24h or negative → null).
Partial cherry-pick from garrytan/community-mode — non-breaking parts only.
Skips install_fingerprint rename (needs schema migration).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>