Fix Type 12 SF field and sync TESTING.md

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/.

examples/build/shift_sf_test.dsp

@@ -0,0 +1,20 @@
+	.section/PM program0;
+	.global _start;
+_start:
+	si = 0x00FF;
+	i0 = 0x0100;
+	m0 = 1;
+
+	/* Type 12: all SF variants with DM read */
+	sr = lshift si (hi), mx0 = dm(i0,m0);
+	sr = lshift si (lo), mx0 = dm(i0,m0);
+	sr = sr or lshift si (hi), mx0 = dm(i0,m0);
+	sr = sr or lshift si (lo), mx0 = dm(i0,m0);
+	sr = ashift si (hi), mx0 = dm(i0,m0);
+	sr = ashift si (lo), mx0 = dm(i0,m0);
+	sr = sr or ashift si (hi), mx0 = dm(i0,m0);
+	sr = sr or ashift si (lo), mx0 = dm(i0,m0);
+
+	nop;
+_halt:
+	jump _halt;