… log

Codex P2 review catch — the "Stub honesty check" block was echoing
results[0].stub but always exiting 0, which undermined the anti-#219
safeguard the script claims to enforce. In Phase 0/2 runs, a non-stub
or malformed response could look like a successful sweep in automation.

Fix: after extracting the flag, case on it:
  - true  → OK, echo success (Phase 0 stub honored)
  - false → FAIL exit 3, diagnostic message naming two possible causes
            (server running non-scaffold code OR wrong endpoint hit)
  - *     → FAIL exit 3, points at the malformed response section

The fix embodies the session's own principle ("the object does the
work" / "stub flag is machine-checkable anti-#219"): a script that
claims to check a flag but doesn't exit on failure is exactly the
pattern we warn against in CODING_PRACTICES.md. The script now
actually enforces what it documents.

Cross-ref: PR #239 D3.2; EPIPHANIES.md 2026-04-20 "D0.2 stub flag is
anti-#219 defense at the type level"; Codex P2 review 2026-04-21.

https://claude.ai/code/session_01SbYsmmbPf9YQuYbHZN52Zh

… construction)

Applies the CODING_PRACTICES "builder is the only path" principle at
the type-system level. Ten key Wire DTOs now forbid raw struct-literal
construction from external crates:

  WireCalibrateRequest       WireSweepGrid
  WireCalibrateResponse      WireSweepRequest
  WireCodecParams            WireSweepResult
  WireTensorView             WireSweepResponse
  WireTokenAgreement         WireTokenAgreementResult

External callers (hypothetical downstream consumer crates) are now
forced through one of these paths to construct these types:

  1. serde deserialize — JSON/YAML at REST/gRPC ingress (the intended
     path per Rule F "serialise once at edges only")
  2. TryFrom<WireCodecParams> for CodecParams — the shipped validated
     conversion that runs precision-ladder + overfit guard
  3. Future Builder::build() if one is added for a specific DTO

Internal construction (tests in wire.rs, grpc.rs conversion code,
serve.rs handler body) is UNAFFECTED — #[non_exhaustive] only
gates external-crate callers. Same-crate code retains struct-literal
access.

Why this matters in practice:

  - `WireCodecParams { subspaces: 6, centroids: 0, ... }` compiled
    today (skipping the ZeroDimension guard). External users can now
    only get a CodecParams through the TryFrom conversion, which
    runs the full validation chain at ingress.

  - Future new fields on these DTOs won't break external callers
    (they were already non-exhaustive-forbidden from raw struct
    literals), so downstream rebuilds don't need coordinated updates.

  - The "object does the work" principle now has teeth — the type
    system enforces what the docs say.

Test Plan:
  - cargo test --features lab --lib:   118/118 pass (unchanged)
  - cargo clippy --features lab -- -D warnings:   CLEAN
  - No internal construction path broken (tests + grpc.rs +
    serve.rs handler all inside the crate)

Also in this commit (cherry-picked from orphan branch state that was
not in the #239 merge):

  - scripts/codec_sweep.sh: Codex P2 fix — stub honesty check now
    exits 3 on missing/false flag instead of just logging. Script
    actually enforces the anti-#219 safeguard it documents.

  - CODING_PRACTICES.md: polyfill chain diagram + mandatory cargo
    clippy + feature-matrix discipline section (~131 LOC).

Cross-ref: CODING_PRACTICES.md anti-pattern #10 "Raw struct literals
bypassing builders"; session epiphany "the object does the work";
Codex P2 review 2026-04-21 on the stub honesty script.

https://claude.ai/code/session_01SbYsmmbPf9YQuYbHZN52Zh