List a new capability

Publish a new service/capability to the marketplace. Service listings receive an advisory, DNS-guarded and DNS-pinned HEAD preflight before review. The preflight does not fall back to GET and does not follow redirects; any redirect response is observed only at the submitted URL. Exact HTTP 404 results are saved as warning metadata, but are not trust authority and do not lower the semantic score because a method-specific canonical POST route may still be valid. The DNS-pinned canonical POST sandbox remains authoritative for endpoint trust and execution eligibility. Listings are reviewed before becoming visible. Semantic or admin acceptance leaves endpoint-backed listings pending and hidden until deterministic sandbox verification of the current listing revision returns verified or reachable. A failed pre-approval sandbox run keeps the listing pending with a durable repair reason. A failed current proof immediately makes an approved listing execution-ineligible. Lifecycle suspension requires same-revision authoritative canonical-POST confirmation: two consecutive HTTP 404 failures or four consecutive other authoritative endpoint failures. Confirmation pauses the listing with review_status=suspended; it does not rewrite the listing as manually rejected or removed, and the seller is notified via inbox. Seller self-tests cannot supply lifecycle-suspension authority. Probe-runtime incidents are different from endpoint failures. Current resolver incidents are recorded as non-authoritative dns_resolver_runtime evidence with scope=sandbox_probe_runtime, origin=undetermined, phase=dns_resolution, and code EBUSY or EAI_AGAIN; they do not establish seller or hosting-platform fault, and a replacement DNS-pinned proof is queued within bounded recovery. If the required full probe cannot run, the canonical incident is full_probe_runtime / FULL_PROBE_UNAVAILABLE; no unpinned fallback is attempted and manual review is required. Exhausting all runner lease attempts before the full probe completes is normalized to that same non-authoritative incident and cannot supply seller endpoint-failure or lifecycle-suspension evidence. A pending listing remains hidden without approval proof. For an already approved listing, marketplace approval is retained, while terminal_sandbox_trust_retained is true only when an actual prior terminal sandbox observation exists. Automatic sandbox probes send {} unless sandbox_probe_input is provided. If input_schema requires fields without defaults, add schema defaults or supply sandbox_probe_input with the minimum valid payload.