HTTP remote retains error policy and caller signal

Invariants: I8, I9, I10, I13.

An AppError with status 502 and retryable=false previously retained that recommendation through direct CLI invocation but lost it through HTTP remote composition. The HTTP error envelope omitted the declaration, so the remote tool derived true from the status. Independently, implementRemote called the typed method without its request options, discarding caller signal.

The canonical ErrorEnvelope carries an optional boolean retryable only when explicitly declared. ApiError preserves it as an eighth constructor argument; its existing seventh ErrorOptions argument remains compatible. Both HTTP adapters and framed contract-stream errors carry the declaration. implementRemote translates recognized errors through AppError, retaining details, hint and trace metadata; unexpected local transport errors remain raw for the existing safe normalization boundary and internal cause observers.

This metadata does not change the HTTP transport’s retry engine. Undefined retains its previous meaning. A closed consumer error schema must accept the optional field before its producer begins declaring it; streams keep strict boolean validation.

implementRemote calls the existing withOptions method with RuntimeContext.signal. One shared endpoint argument predicate chooses the existing argument/no-argument overload. Pre-aborted calls and cancellation during an asynchronous argument transform dispatch no HTTP request. Local cancellation becomes safe REQUEST_ABORTED, status 499, retryable=false, CLI exit130; a local deadline is REQUEST_TIMEOUT, status408, exit7, retryable=false.

Cancellation stops the caller’s HTTP operation. Cooperative server handlers observe their request signal and release permits and locks in their actual completion path. An origin or external provider ignoring cancellation may continue; a rejected wait never substitutes for physical completion. Installed probes observe a real listener, live permits/locks, an ignoring origin and a genuine compiled CLI receiving SIGTERM, independently of local invocation results.

No second HTTP client, remote executor, signal lifecycle or consumer error renderer is added.