FLX-1007: two mapping keys collide after canonicalisation

Family: canonicalisation (the 1000 band)

NFC normalisation and key coercion (KERNEL-SPEC §2.1) can map two distinct source keys onto one canonical key -- for example True and 'true', or the composed and decomposed spellings of the same word. Merging them would silently drop a value, so the document is refused.

Look it up offline

$ fluxsim explain FLX-1007

Every code is listed in the error index.