L08-08 — Gate free-text slots behind a single-key text helper #261

Outcome

Allow free text only where a task declares a typed text slot (for example, explanation prose for a finding), following jev's TYPE_TEXT helper. The helper runs only when the validated observation selects an operation that owns a text slot. It receives a minimized context (task, selected row, cited evidence rows, recent decisions) and must return exactly one JSON key, {"text": "…"}, or {"text": null} when the evidence does not support an answer. The text cites row indices and is display-only.

Parent and boundary

Parent: #9. Owner: proposed Decision module. This issue owns one bounded slice of Bounded Decision Worker; consume accepted upstream contracts and keep PDF/verdict/publication authority with Core.

Acceptance

• Output with extra keys, a non-string value, an empty string, over-length text, or a citation of a non-offered row is rejected. Nothing is shown and the deterministic explanation from L08-02 — Build deterministic no-provider policy over the same action space #62 remains.
• A generated value is reused only while the entire helper input digest is unchanged (jev's stale-retry cache). It is discarded after the observation is consumed.
• Text never becomes a plan field, parameter, Core identity, or verdict, and it is not a deciding input to any later question.
• Failure case: a helper that invents values, follows instructions embedded in document text, or runs without a selected text-slot operation fails.

Required proof

Strict-JSON parser fixtures, null/unsupported cases, a cache-invalidation test, an injection test shared with #64, and a no-provider fallback test. Record the exact source SHA, test command or hosted run, fixture/artifact identity, and any skipped or unavailable lane. Run the repository's mapped proof and check-change gate for a PR.

Handoff

Record changed files, observed result, remaining risk, and a 1–3 sentence anti-slop review. Completion means acceptance evidence, not merely a merged implementation.

Sources

Approved master roadmap · North Star: jev-ultrafast@1231850a; see the translation table in #9.

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