Module format_cache 

Per-message formatted-line cache.

Thread-local cache keyed by (timestamp_nanos, content_len, max_width, role). ChatMessage content is immutable post-construction, so formatted lines can be reused across frames until width or content changes.

Functions

format_message_cached

Format message.content for role at max_width, reusing prior parses.

reset_format_cache

Clear the entire cache.