Add SEP: Contract Verification Registry API

[fnando]

Adds a new Draft ecosystem proposal, Contract Verification Registry API, defining a read-only HTTP API for querying whether a smart contract's wasm has been reproduced from its source.

What it covers

• A status endpoint that looks a contract up by wasm hash and returns the verifications one or more verifiers have recorded for it.
• Reuses the SEP-58 vocabulary verbatim (bldimg, bldopt, source_repo, source_rev, tarball_url, tarball_sha256) — this SEP is a transport for SEP-58 results and adds no vocabulary of its own.
• JSON Schemas for the status object and error responses (status-object-1.0, error-1.0).
• Worked examples covering verified, unverified, pending, out-of-band, multi-verifier, and error cases.

Why

This standardizes the API surface for the Contract Source Verification Service RFP. With a common interface, any verification service can implement the API and any client can consume verification results interchangeably, regardless of which service produced them.

Status: Draft — SEP number to be assigned.

👉🏻 Discussion thread 👈🏻

[Copilot]

Pull request overview

This PR introduces a new Draft SEP (“Contract Verification Registry API”) that standardizes a read-only HTTP endpoint for querying whether a contract wasm has been reproduced from source, along with JSON Schemas and extracted example fixtures to validate implementations.

Changes:

• Adds a new Draft SEP specifying GET /wasms/:wasm_hash.json, response semantics (200 vs 202), and a status-object format that reuses SEP-58 vocabulary.
• Adds JSON Schemas (draft 2020-12) for the status object and the optional 400 error body.
• Adds extracted JSON example files (status + error) and a README explaining how to validate them.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
ecosystem/sep-contract-verification-registry.md	Defines the proposed HTTP API, response objects, error shape, and rationale/security notes.
contents/sep-contract-verification-registry/status-object-1.0.schema.json	JSON Schema for the 200/202 status object.
contents/sep-contract-verification-registry/error-1.0.schema.json	JSON Schema for the optional 400 error body.
contents/sep-contract-verification-registry/README.md	Documentation for schema/example layout and validation commands.
contents/sep-contract-verification-registry/examples/status/202-pending.json	Example fixture for an enqueued/in-progress (202) response body.
contents/sep-contract-verification-registry/examples/status/200-verified.json	Example fixture for a verified (200) response body.
contents/sep-contract-verification-registry/examples/status/200-unverified.json	Example fixture for a settled unverified (200) response body.
contents/sep-contract-verification-registry/examples/status/200-two-verifiers.json	Example fixture for multi-verifier disagreement (200).
contents/sep-contract-verification-registry/examples/status/200-out-of-band.json	Example fixture for out_of_band verification (200).
contents/sep-contract-verification-registry/examples/error/400-other.json	Example fixture for the generic 400_other error body.
contents/sep-contract-verification-registry/examples/error/400-invalid-wasm-hash.json	Example fixture for 400_invalid_wasm_hash error body.