Codex CLI 0.150.0-alpha.1

• [new] MCP server event streaming: start and stop an event stream for an MCP server, with matching stream/event notifications on the app-server protocol.
• [new] Shell snapshot support in the exec server, including snapshot request handling and related shell snapshot state.
• [new] exclude_slash_tmp config key for controlling whether /tmp-style paths are excluded.
• [changed] Shell tool execution is reworked around a dedicated zsh-fork runtime (including Unix escalation), replacing the previous shell handler/runtime layout.
• [changed] OpenTelemetry config and tool-result reporting are extended so tool outcomes can be exported more completely.

Under the hood

• First-party shell code is reorganized: legacy shell handlers/runtimes are removed in favor of the zsh-fork runtime modules; exec-server gains shell snapshot and accepted-client pieces and drops the old relay v1 proto path.
• App-server request processing adds an MCP event-stream path; related MCP stream start/stop params and notifications are part of the typed protocol surface.
• Config/requirements models grow slightly (including analytics and requirements TOML shapes, thread/model defaults, and several small API response types).
• rmcp / rmcp-macros bump from 3.1.2 to 3.1.3, with a few supporting crate additions in the lockfile.
• Internal CODEX shell-related environment grouping and exec-server/shell-snapshot knobs continue to evolve alongside the runtime changes.