docs: add product technical gap baseline

CHANGELOG.md

@@ -7,6 +7,7 @@ All notable changes to TEPP are documented here. The format follows Keep a Chang
 ### Added
 
 - `tepp_api` naruon live loopback HTTP/1.1 listener: `serve_one` installs a read/write deadline, requires a loopback `Host`, refuses `Transfer-Encoding` and NIM/proxy credential headers, parses `knowledge_cutoff` as RFC 3339 and refuses a future cutoff, keys analysis-run idempotency by tenant plus key, and proves both analysis-run and export POSTs over a real `TcpStream`. Not a production TLS/`$PORT` service (ADR 0011).
+- Product/technical buyer-gap baseline linking approved product and architecture decisions to live PR, review, check, scientific, security, privacy, operability, and ecosystem evidence; each gap includes a bounded next customer action and exact-head refresh rule.
 - `tepp_api` adaptive orchestration router (ADR 0010): versioned `direct`/`verify`/`committee`/`conductor`/`abstain` selection from CPU `f64` risk, ambiguity, evidence, and token-budget inputs; recorded stages, recursion, decomposition, access lists, and role-specific reasoning effort; fail-closed document-controlled policy/access/credentials; LLM plans remain proposals under deterministic statistical authority; comparable-budget ablation requires a direct baseline; credential-free contextual-orchestrator binding. Live NIM HTTP remains accepted-target.
 - `tepp_api` purpose-bound provider-payload minimization: time-bounded `PurposeGrant` evaluation, fail-closed expired/not-yet-valid/inverted/cross-tenant/impossible-calendar denial, semantic UTC calendar validation, refusal to copy identity mappings into model-provider payloads or ordinary logs, preservation of opaque analytical identifiers and membership roles (no blanket PII mask), a separately authorized scientific re-identification path, and an internally bound FIPS 180-4 SHA-256 audit digest appended through `ReidentificationAuditSink` before disclosure.
 - `persistence_postgres` backup/restore integrity: restored snapshots stay unusable until tenant, canonical `SHA-256`, knowledge-cutoff eligibility, temporal window order, and append-only triggers revalidate; SQL probes raise `restore integrity failed` (ADR 0013).

DOCUMENTATION.md

@@ -21,6 +21,7 @@ TEPP's approved PRD v0.4 and implementation plan are the primary product baselin
 | Test/scientific validation strategy | [`docs/TEST_STRATEGY.md`](docs/TEST_STRATEGY.md) |
 | Operability/recovery/release | [`docs/OPERABILITY.md`](docs/OPERABILITY.md) |
 | Requirement/research/evidence traceability | [`docs/TRACEABILITY.md`](docs/TRACEABILITY.md) |
+| Product/technical buyer-gap baseline | [`docs/product-technical-gap-baseline.md`](docs/product-technical-gap-baseline.md) |
 | Architecture decision index / ownership map | [`docs/adr/README.md`](docs/adr/README.md) |
 | ADR status, maturity, and supersession policy | [`docs/adr/ADR_POLICY.md`](docs/adr/ADR_POLICY.md) |
 | Delivery roadmap | [`docs/roadmaps/2026-08-05-tepp-delivery-roadmap.md`](docs/roadmaps/2026-08-05-tepp-delivery-roadmap.md) |