[sleeyax]

Closes #139.

When a claude-tty request handler failed, Paseo showed only Internal error, even though the adapter had thrown an error that said what went wrong.

The adapter throws plain Errors. @agentclientprotocol/sdk answers any error that isn't a RequestError with JSON-RPC -32603 and the message Internal error, and puts the real text in data.details. Some Paseo daemons drop data entirely. Paseo 0.11.2 keeps it, but shows it behind the prefix: Internal error: Claude never took the prompt….

What this changes

• Errors keep their own message (withRequestErrors in src/request-errors.ts): it wraps the agent before main.ts hands it to the SDK. When a handler throws, the error is rethrown as a RequestError whose message is the error's own text. A RequestError thrown on purpose passes through unchanged. Because there is one wrap point, no throw site changed.
• The code stays -32603: Paseo 0.11.2 (providers/acp-agent.js) treats only -32602 differently, using it for its set-model fallback. With no data attached, it shows the message as-is.

Verification

• New tests: one connects a client and the adapter through the SDK, sends a prompt to a session that doesn't exist, and checks the client gets Session missing not found. Without the wrapper, the same test gets Internal error. Another test checks that a RequestError passes through as it was thrown.
• Checks: claude-tty-acp typecheck is clean and 247 tests pass.

Not covered

• A multi-megabyte paste still fails, because the adapter waits about 2.3 s for the paste to show up in the input box. That failure now carries its own sentence, but the timeout itself is the separate question raised in claude-tty: adapter errors reach Paseo as a bare "Internal error" #139.

[sleeyax]

Closing: Paseo already shows data.details (since at least 0.10.3), so this only drops the Internal error: prefix and doesn't fix the bare Internal error reported in #139.