Fast mode gating and per-session opt-in logic reworked

What

The logic controlling fast mode (internally called "penguin mode") was changed in a few ways:

• Organization-status handling for fast mode is now split depending on whether the session is an SDK-style context, using new helper logic.
• A per-session opt-in check gained a sessionOnly parameter.
• A new auto-trigger prefetches the organization's fast-mode status whenever settings show fastMode=true but the org status is still pending or assumed disabled.
• Separately, the policy override gate for fast mode now applies whenever policySettings.fastMode === false, even if the caller did not explicitly request fast mode for that request; previously this override only took effect when fast mode had already been requested.

Why

These changes make fast-mode eligibility checks more consistent across SDK and non-SDK contexts and ensure an organization policy that disables fast mode is enforced even when a particular request didn't ask for fast mode, closing a gap where the override could be skipped.