v0.9.2 - ACP spec conformance updates

Added

• ACP Registry helpers - ExMCP.ACP.Registry can fetch, parse, search, and build npx commands from the public ACP Registry.
• ACP handler runner - Agent-originated requests and session update handlers now run outside the ACP client process, so slow permission, file, terminal, or update handlers cannot block streamed updates or prompt completion.
• MCP 2025-11-25 conformance coverage - Conformance scripts and tests now cover the latest supported MCP spec version and updated server behaviors.

Changed

• ACP stable spec alignment - Updated ACP method names, content/resource builders, permission responses, terminal delegation, config options, prompt capabilities, session capabilities, and adapter update shapes to match the current stable ACP v1 schema.
• Adapter update normalization - Claude, Codex, and Pi adapters now emit stable agent_thought_chunk, tool_call, and tool_call_update shapes for core streaming and tool lifecycle events.
• Prompt text handling - Client.prompt/4 now folds streamed agent_message_chunk text into the returned result when agents stream the answer instead of returning inline text.

Fixed

• Permission cancellation - Client.cancel/2 now replies to pending session/request_permission requests with the required cancelled outcome without waiting for a blocked handler.
• MCP protocol edge cases - Updated method handling and version registry tests for newly covered MCP conformance cases.