Constant CANONICAL_STRINGS 

pub const CANONICAL_STRINGS: &'static [&'static str];

Canonical strings the warmup shapes through cosmic-text so the per-face shaping caches are populated before the compositor’s first real widget draw. Kept small so the warmup thread stays under ~50ms wall time even on a cold fontconfig cache.

Covers Latin-1, common CJK (JP+CN+KR overlap), and a four-emoji fallback probe — enough to force every fallback family the shell chrome hits on first paint (workspace name pill, tab titles, clock, notification body).