v0.9.0 (2026-08-14)

• Pin grok to a concrete model instead of riding the provider's rolling default. codex has always resolved sol/terra to a pinned id; grok was the one backend where cdx sent no -m at all and let the CLI pick, so a provider-side default flip could change what runs between two spawns of the same fleet, and result reported model: null — the task never recorded what it actually ran on. --effort/--model overrides are unaffected: an explicit --model still wins.
• Raise grok's effort ceiling from high to xhigh, so --effort max means the same everywhere. The old cap dated from grok's --reasoning-effort accepting any string unvalidated; it now validates against low|medium|high|xhigh and rejects the rest with an error event. Verified against codex-cli 0.147.0, claude 2.1.232 and grok 1.0.3: all three CLIs keep the flags, event shapes and resume paths cdx depends on, and both codex and claude have since gained a max tier above xhigh — deliberately left outside cdx's surface, because it costs a lot for little gain.