//! Shared rendering functions used by both App (diff mode) and `ViewApp` (view mode).
//!
//! These pure rendering functions take domain types directly (`&QualityReport`,
//! `&Violation`) with no app-specific dependencies, enabling both TUIs to
//! delegate to common code.
/// Find the largest byte index <= `index` that is on a UTF-8 char boundary.
///
/// Equivalent to `str::floor_char_boundary` (stabilized in Rust 1.94,
/// but our MSRV is 1.88).
pub const