2.2.0

Agent errors are JSON with a code, so scripts and agents can handle them without reading the message.

Changes

• The hammer tool prints failures as one JSON object on standard error, {"code", "error", "hint"}, like successful output. MCP tool errors carry the same object.
• Errors have codes such as not_found, not_hittable, ambiguous_target, timed_out, unreachable and invalid_arguments, in the new AgentErrorBody.code.
• Commands can report their own codes, like throw AgentError.failed("No test user", code: "unknown_user"). Code that pattern matches AgentError.invalidArguments or .failed needs a third value.
• When the app drops the connection or times out, the hint says the command may have run, so check the app's state before running it again.

What's Changed

• Report agent errors as JSON with a code by @gabriellanata in #90

Full Changelog: 2.1.1...2.2.0