Type 12: SF is 4 bits (15-12), D is bit11 (not SF=3bits, D=bit12).
Verified all 8 SF variants against assembler: LSHIFT/ASHIFT,
HI/LO, plain/OR. FIR output scaling chain now correct.
TESTING.md: Synced with actual verification status.
34 of 37 types now assembler-verified.
Only Type 22/22a (2-word data write), Type 31 (IDLE), and
Type 32a (DAG store+transfer) remain structural-only.
Removed build artifacts (.o, .elf) from examples/build/.
- Header no longer claims 'complete' — lists verified vs structural types
- Add TESTING.md with per-type coverage status and priority gaps
- 17 types assembler-verified, 20 types structural only
