Claude: offer ultracode in the effort pill #741

Parent: #738
Needs: per-model effort lists (child of #738) if Haiku stays in the same provider

User-visible bug

Claude's effort pill is low | medium | high | xhigh | max. Claude Code 2.1.203+ also accepts ultracode: session setting that sends xhigh plus automatic Dynamic Workflows (multi-agent orchestration). Users of the raw CLI set it with /effort ultracode or claude --effort ultracode. Solenta cannot.

This is not a sixth API effort. Anthropic's API enum remains low through max. Ultracode is a Claude Code harness mode. The pill should still offer it, with copy that says so, because that is the CLI surface.

What to ship

1. Live-check on a logged-in claude 2.1.203+ that --effort ultracode is accepted. This machine is 2.1.219 but org-auth disabled, so the flag was not confirmed here. claude --help still lists only low/medium/high/xhigh/max. Unknown values are a silent warning plus default: do not ship on help-text alone.
2. If accepted: add "ultracode" to ReasoningEffort (or a Claude-only extra token if we want to keep the shared union API-shaped). Prefer the shared union so the pill stays one control. Label: "Ultracode". Secondary copy: "xhigh plus workflow orchestration, this session".
3. Claude buildArgs already emits --effort <level> via maybeEmitEffort. Add ultracode to Claude's allow-list. Hide it on Haiku (not effort-capable).
4. Persistence: third-party docs say ultracode resets when the session ends and cannot live in effortLevel / CLAUDE_CODE_EFFORT_LEVEL. Confirm against the live CLI. If it is session-only, either (a) still persist on the Solenta thread and re-send --effort ultracode every spawn (likely what we want), or (b) treat it as a per-turn override. Do not drop it on resume if the CLI honouring --effort on --resume is verified.

Do not

• Do not map ultracode to xhigh-only. That loses the workflow half.
• Do not add Claude Mythos 5 without a live /model listing on a logged-in CLI.

Files

electron/providers.js (Claude efforts + buildArgs), src/shared/ipc.ts, src/modelPicker.ts, electron/store.js, electron/test/reasoning-effort.test.js.