Remove three never-used surfaces flagged in branch self-review:
- PromptSource::writer / with_writer (unwired since the crate's first
commit; Arc<dyn Write> couldn't even be written to without interior
mutability, so the seam never worked as intended)
- OidcSession::is_openbao_token_expired (duplicated is_expired, no callers)
- HARMONY_SECRETS_URL env var (defined, never read)
Log before swallowing real StoreSource::get errors so a down or
misconfigured OpenBao is no longer indistinguishable from "key absent".
Docs: ADR 020-1 now documents the actual OPENBAO_URL/VAULT_ADDR var (the
agnostic HARMONY_SECRETS_URL it proposed was never built) with the
adapter-layer-vs-domain rationale; rename stale ConfigManager references
to ConfigClient in ROADMAP/01 and a firewall_pair comment.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Sylvain Tremblay
aba36b1b69