docs(reflex): add calibration passport guidance

[0xnavarro]

Public change

Strengthens provider-neutral engine/calibration guidance for Reflex without changing any contract, recipe, fixture or hosted behavior.

Adds:

• a versioned calibration passport tying thresholds to contract/question, engine/checkpoint, runtime/backend, primitive/cardinality, workload slice and calibration corpus/artifact;
• explicit separation between answer-distribution probabilities and a separate correctness/selective-automation signal when an engine exposes both;
• runtime/conversion semantic-fidelity checks before comparing latency/throughput;
• corresponding verification guidance in the general Brida Reflex skill.

Why

A stable Reflex contract can be served by multiple engines and runtimes whose probability scales and numerical behavior differ. Schema/API compatibility is not semantic equivalence, and one engine's threshold or confidence interpretation must not silently transfer to another.

Authority / compatibility

Documentation only.

No public schema, Custom Reflex definition, use-case ID, recipe, fixture expectation, SDK API, hosted execution route, data-class rule or authority boundary changes.

Privacy / provenance review

• provider-neutral wording only;
• no external source attribution;
• no private research URLs/IDs;
• no third-party benchmark claims;
• no engine/vendor-specific product identity.

Validation intent

• public CI / registry validation;
• skill structure/sync checks;
• public-surface/full-history leak scan;
• diff hygiene.

Release intent

• release-impact: none
• release-note: none
• qa-scope: docs

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
🔒 Security Review	✅ Completed 2026-09-22T20:13:58.882532Z	680e4da	PR opened

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.