test(focas): bring the vendored focas-mock onto the real 31i-B wire shapes; integration tests follow

The mock had served the shapes the driver once agreed with it on, so it
validated the very defects just fixed: it ANSWERED the non-existent 0x00D3
cnc_getfigure, wrote base/exponent 0/0 into position blocks, put the macro
decimal at offset 4, and served spindle 'max rpm' as a raw constant.

Ported from the sister ignitionoee mock (local divergence recorded in
VENDORED.md; the LE timer and alarm cap are kept):
- 0x00D3 refused with EW_FUNC, as the real control does.
- 0x0026 blocks carry base 10 / position_figures exponent; signed arg2,
  arg2 = 0 or past the axis count refused EW_ATTRIB.
- cnc_rdmacro is the 8-byte ODBM shape, 9-digit mantissa, unset = vacant.
- servo/spindle meter records carry the envelope; spindle meters are
  1/16384-of-full-scale counts (motor speed = speed / max_rpm).

Integration tests: spindle test reads Load/MotorSpeedPct percentages; the
position-scale test now proves the block's own scale wins; new
Vacant_positions_and_macros_read_bad_over_the_wire. 12/12 pass against the
mock run locally (python -m focas_mock.cli serve, OTOPCUA_FOCAS_SIM_ENDPOINT).

tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.FOCAS.IntegrationTests/Docker/focas-mock/VENDORED.md

@@ -43,3 +43,18 @@ Copy-Item "$src\Dockerfile" "$dest\"
 Update the snapshot date at the top of this file afterward. No other
 files belong here — the Docker build context is just the Python package
 and its metadata.
+
+## Local divergence (do not lose on refresh)
+
+`src/focas_mock/server.py` and `defaults.py` carry OtOpcUa-local edits that make the wire
+shapes match a real FANUC 31i-B (Makino Z-34184) instead of shapes the driver and the mock had
+agreed on between themselves. A refresh that overwrites `src/` must re-apply them:
+
+- the little-endian `cnc_rdtimer` minute/msec encoding (2026-06-25, live-validated);
+- the alarm count cap on `cnc_rdalmmsg2`;
+- (2026-10-07, ported from the sister ignitionoee FOCAS mock) `0x00D3` ("cnc_getfigure", not a
+  real FOCAS wire command) refused with `EW_FUNC`; `0x0026` position blocks carrying their own
+  `base/exponent` (`position_figures` is now that exponent) and a signed `arg2`;
+  `cnc_rdmacro` as the 8-byte ODBM shape (`dec_val` at `[6..7]`, 9-digit mantissa, unset
+  macro = vacant); servo/spindle meter records with the `base/exponent` envelope, spindle
+  meters in 1/16384-of-full-scale counts.