Render a bank's disposition traits into behavioural prose for the reflect prompt (D6). Faithful port of Hindsight's engine/search/think_utils.py build_disposition_description + describe_trait_level, activating the stored disposition_skepticism / disposition_literalism / disposition_empathy fields that were otherwise inert.

Traits are levels 1-5 (1=trusting/flexible/detached, 5=skeptical/literal/empathetic). Deviation from Hindsight (intentional): an absent disposition renders "" rather than Hindsight's always-present 3/3/3 default, so banks that set no disposition keep a clean prompt. Once ANY trait is present, all three render — a missing one defaults to moderate (level 3), matching Hindsight's .get(value, desc[3]).