Gson/Jackson/fastjson2/Moshi bind fields by reflection from a Class
literal, with no field-name string for the string-based detection:
renaming such a field silently breaks deserialization. Absorb_databind
finds the nearest Const::Class before fromJson/readValue/parseObject/
adapter calls (10-insn window, control-flow boundaries stop the search)
and keeps every field of that class; the class itself still renames.
Tests: noxis-analysis/tests/dto.rs (red first), keep unit tests moved
to tests/keep.rs (file budget). Code comments migrated to English.
