v1.9.3 review fixes: CLA doc ranges, README_RUS, mirror/ODD_INS pins

- pd.py/AGENTS: the rejected '8X' range now reads 0x81-0x83/0x85-0x8F
  (0x84 stays accepted); the 0x40-0x4F vs 0x50-0x5F citations are split
  (chaining is ISO-only, TS 102 221 keeps b5=0); the bit-dense CLA list
  gains 0xE7 (exact set verified).
- README_RUS.md: the invalid-INS note mirrored (the removed odd-LSB rule,
  citation corrected to 5.1.2).
- tests: test_vs_reader_mirror (pd.py <-> tools/vs_reader.py drift guard),
  test_odd_ins_set_pinned, the 0xE7 noise vector, and the 'EX' vector now
  uses STATUS (e2 f2) as TS 102 221 Table 10.5 defines.
- tests/baseline.txt regenerated (test listing only); compare_baseline:
  IDENTICAL.

tools/vs_reader.py

@@ -95,8 +95,9 @@ def embedded_exchanges(buf):
     embedded inside a packet's data region (index 5 onward).
 
     Pattern: header (CLA INS P1 P2 P3) + P3 data bytes + interior SW1/SW2
-    before the packet's own final status word.  CLA must be structurally
-    valid (same rule as _plausible_cla); INS must be a real command byte;
+    before the packet's own final status word.  CLA must be one of the
+    pinned EMBEDDED_CLA classes (deliberately narrower than
+    _plausible_cla()); INS must be a real command byte;
     SW1 is accepted within a small slack window after the nominal data end
     and must be interior (trailing bytes follow it).
     """