[MMinasyan]

Changes

• Replace the engine's invocation-wide context and tool advertisement with one request source supplying a complete validated model request per round; tool dispatch receives the producing request's advertised names, with the argument, extra and names containers handed to each call as owned copies, so a callback cannot alter the retained settled output or a sibling's authority.
• The durable tool gate checks the committed call's name against the advertisement of the request that produced it; later requests and mutable caller data cannot broaden that authority.
• Add the ordinary standalone adapters over the included transport (one attempt, completed/errored/interrupted settlement mapping, cancellation settled as interruption) and the tool map (copied at construction; missing, unadvertised or unregistered names settle as unavailable results). Document the client and loop as the independently usable engine surface.

Tests

• Regressions cover per-round advertisement changes and mutation barriers, per-call owned dispatch names, argument and extra clone isolation, the producing-request gate with no retroactive authority from later requests, and adapter mapping rows including verbatim callback errors and a single physical attempt per invocation.
• Full Go suite, race suite, frontend suite, protocol fixture corpus, generated-binding freshness and the Wails build passed.
• A consolidated review round ran; its findings were fixed or dispositioned with recorded reasoning, and the follow-up fix passed a consolidated review.