TEXT oblique_angle / rotation_angle / width_factor read as BD where §20.4.3 types them RD — latent divergence no sample exercises

[DrunkOnJava]

From #58: every TEXT record in the corpus sets the DataFlags bits that suppress these three fields, so the BD reading is untested either way. If a file clears those bits, a BD read would misalign (BD has a 2-bit prefix; RD is raw 64). Decide from the spec text + a file that clears the flags (synthesize one via examples/build_fixtures.rs once the writer can emit TEXT with those fields, or find a permissive sample); fix and pin with a BitWriter test. Same audit for ATTRIB/ATTDEF which share the TEXTFIELDS composite.