Require `trio>=0.34.0`, the version exercised with object-valued
`Cancelled.reason` payloads in the downstream ctx experiment.
Resolve `uv.lock` with `trio` at `0.34.0`; also synchronize the
existing `py-multibase` requirement. No other package version moves.
Prompt-IO: ai/prompt-io/opencode/20260919_trio_reason_minimum.md
(this patch was generated in some part by `opencode` using
`gpt-6-astra` (`openai`))