REL-06 cross-client and result acceptance

Server base 32ecaf61b2305852c60b0cc4e2682a149c8e5b07; branch codex/release-acceptance. Bridge candidate 496c5e987c5b0582a79f5cf1d123e85df040523e. All fixtures are synthetic.

Actual validation on 2026-09-22:

• Full server suite against fresh PostgreSQL 16: 250 passed in 10.62s, zero skipped tests. This includes two mandatory cold-client acceptance tests.
• Actual Bridge release binary with Python HTTP server and PostgreSQL, plus cold-client controls: six acceptance tests passed in 18.76s before moving the two cold tests into mandatory server CI (four provider/process tests remain in the release-only acceptance directory).
• Both real Codex and real Claude applied the pinned profile skill. Checks inspect structured agent response text, not an echoed prompt. Each process returned zero with an unchanged clean Git base and exactly one work receipt.
• A different explicitly selected workspace is rejected before claim.
• A producer MCP process writes only a Git reference/digest into a task and exits. A separate consumer receives only connection configuration and the user-selected workspace, discovers the task via continuity_context and independently verifies the exact Git object before completing it.
• Negative control: an incorrect digest leaves the task open and creates no completion receipt.
• Generated MCP contract, 18-tool documentation coverage, runtime validation, website consent tests and strict MkDocs passed.

The cold test proves deterministic protocol continuity across disconnected client processes. It does not certify arbitrary autonomous AI task handoffs. Likewise process completion is not independent verification of arbitrary test claims. The existing explicit completion/receipt boundary remains intact.

The deployment canary now checks both new execution read routes reject unauthenticated requests, alongside the eight existing health/Bridge routes. Production has not been changed by this acceptance task.