[ENHANCEMENT] Allow follow-up auto-approve timeout of 0 to disable auto-selection #1993

Problem (one or two sentences)

The follow-up question auto-approve timeout is clamped to a 1s minimum, so users who want to disable auto-selection entirely cannot: the first suggested answer is always auto-selected after roughly a second.

Context (who is affected and when)

Users who prefer to read and choose each follow-up manually, or who find the countdown premature or distracting. Most visible during long runs and when the first suggestion is not the one the user wants.

Desired behavior (conceptual, not technical)

Setting the follow-up auto-approve timeout to 0 disables the countdown entirely: no suggestion is auto-selected and the user always chooses. The settings slider allows 0 and shows a dedicated zero-state description.

Constraints / preferences (optional)

• Must remain keyboard accessible and screen-reader friendly.
• Preserve the existing onCancelAutoApproval notification on unmount.
• New/changed setting must follow the existing global-settings round trip (schema, ExtensionState, ClineProvider.getState/getStateToPostToWebview, SettingsView).
• No behavior change for timeouts of 1s or more.

Request checklist

• I've searched existing Issues and Discussions for duplicates
• This describes a specific problem with clear context and impact

Acceptance criteria (optional)

Given the follow-up auto-approve timeout is set to 0
When a follow-up question is shown
Then no countdown runs and no suggested answer is auto-selected
And the user must select an answer manually
But timeouts of 1s or more keep their current countdown and auto-selection behavior
And negative values are treated the same as 0 (disabled).

Proposed approach (optional)

• Short-circuit in FollowUpSuggest when timeoutMs <= 0 (countdown set to null; still notify onCancelAutoApproval on unmount).
• Lower the slider minimum from 1000 to 0 and add a zero-state description when the value is 0.
• Add the zero-state copy across all locales.

Trade-offs / risks (optional)

• Adds one new user-facing string; negligible runtime cost. The zero state is visually distinct, so it is unlikely to be mistaken for the 1s minimum.