kandev/docs/plans/no-silent-model-fallback/task-05-picker-gone-support.md

id, title, status, wave, depends_on, plan, spec

id	title	status	wave	depends_on	plan	spec
task-05-picker-gone-support	Model pickers support disabled (gone) models	done	3		docs/plans/no-silent-model-fallback/plan.md	docs/specs/agents/requirements/no-silent-model-fallback.md

Task 5 — Model pickers: grey out gone models

Change

apps/web/components/model-config-selector.tsx:

• ModelSelectorOption gains disabled?: boolean and disabledReason?: string.
• ModelRow renders disabled options greyed (opacity-40, cursor-not-allowed) with the reason in a tooltip; onSelect guarded by !option.disabled. Follow the existing disabled pattern in apps/web/components/combobox.tsx (visual treatment + tooltip).

apps/web/lib/ws/handlers/session-models.ts:

• clearStaleActiveModel no longer clears the active model when it disappears from the ACP list. Keep it; the picker marks it gone.

apps/web/components/task/model-selector.tsx:

• buildModelOptions / resolveAvailableModels mark the configured-but- absent models (active model, profile model) as disabled with reason "model no longer available — select a new model". The current model display still shows the (gone) model name so the user sees what was active.

i18n: new copy via t() (settings: namespace) — the ratchet judges added lines.

Acceptance

1. Unit test (model-config-selector): a disabled option is not selectable and renders the greyed class; tooltip carries the reason.
2. Unit test (session-models handler): when the ACP models list drops the active model, the active model is kept (not cleared).
3. Unit test (model-selector): a configured model absent from the list is included in options as disabled with a reason.
4. pnpm run typecheck + targeted vitest pass.

Verification

cd apps/web && pnpm vitest run components/model-config-selector.test.tsx lib/ws/handlers/session-models.test.ts components/task/model-selector.test.tsx
cd apps/web && pnpm run typecheck
cd apps/web && pnpm run i18n:ratchet

Risks

• The session picker's option-building has several sources (ACP models, static model config, config options) — the disabled marking must apply to the merged option list without breaking the config-option path.
• Keep clearStaleContextWindow behavior unchanged (that one is about context-window reset on a legit model change, unrelated).