[openapi-mcp S6] Three read tools: contracts, flows, registry wiring, receipts

[rickylabs]

Part of #1126

Scope

The three read tools end to end: list_api_services, list_service_operations, get_operation_schema — contracts in tool-contracts.ts, flows (one file per tool), registry wiring (14 → 17), receipts. Operation counts computed from the parsed spec of the liveness GET or absent — never defaulted (S-14; the rev-1 "HEAD-style" mechanism cannot work: HEAD carries no body). Flows self-cap arrays below the central truncator and compute truncated after their own caps (S-13a). curlExample is an explicitly unauthenticated request template with authNote — executability never inferred from absent security metadata (S-24). Failure envelopes per the single status mapping.

Blocked by S2's verdict artifact; receipt semantics depend on S8 landing (receipts written only after output validation).

Design source: RFC #1123 (rfc.md §3) + design/canonical/01-tool-surface.md (rev 2).

Acceptance

• gate: fixtures prove truncated: true appears whenever any row was dropped, and never coexists with removed rows
• gate: operations count absent (not zero) when no spec was fetched
• gate: sources block from S5 surfaces verbatim in list_api_services output

[rickylabs]

Boxes ticked by the orchestrator on independently re-run fixture evidence (PR #1204): list_api_services reports truncation when service rows are dropped + list_service_operations marks truncation iff at least one matching row was dropped (box 1); forwards sources verbatim and omits counts without a fetched spec (boxes 2+3) — 10/10 green locally on head. Registry wiring and S8 receipt semantics composed from main.