MP: authentic update-record deadbands streamed from the model record (task #3)

Binary ctor @0x4a26a7-0x4a26ef: mech+0x768/76c/770 <- raw record words
0x26/0x27/0x28 (UpdatePositionDiffrence / UpdateTurnVelocityDiffrence /
UpdateTurnDegreeDiffrence x pi/180 [const @0x4a2d44]).  Read at RAW record
offsets -- the Mech__ModelResource struct is layout-skewed (field98 gave
-1.5 where the record holds 0.3; audit filed as task #4, also explains the
old forwardCycleRate "floor 25" hack).  Sender triggers now use the
authored constants: pos-deadband type 0, quat-Y delta + yaw-rate delta +
stopped-turn edge type 4 (binary @0x4aad35/@0x4aac2b/@0x4aac6c).
Verified 2-node: madcat streams 0.3/0.045/3deg, type-4 spam gone, walking
replicant clean.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

scratchpad/scan_deadband.py

@@ -0,0 +1,39 @@
+import capstone, struct, sys
+sys.stdout.reconfigure(encoding="utf-8", errors="replace")
+data = open("../content/BTL4OPT.EXE","rb").read()
+# established mapping (from dis_4b2980.py usage): file offset = VA - 0x400000 - 0xc00 adjustments;
+# use the section table: .text typically RVA 0x1000, raw 0x400/0x600.  Recover from PE header.
+pe = struct.unpack_from("<I", data, 0x3c)[0]
+nsec = struct.unpack_from("<H", data, pe+6)[0]
+opt = pe+24; szopt = struct.unpack_from("<H", data, pe+20)[0]
+sec0 = opt+szopt
+imgbase = struct.unpack_from("<I", data, opt+28)[0]
+secs=[]
+for i in range(nsec):
+    off=sec0+i*40
+    name=data[off:off+8].rstrip(b"\0").decode()
+    vsz,va,rsz,ra=struct.unpack_from("<IIII",data,off+8)
+    secs.append((name,va,rsz,ra))
+text=[s for s in secs if s[0]=="CODE"][0]
+va0=imgbase+text[1]; ra0=text[3]; n=text[2]
+md=capstone.Cs(capstone.CS_ARCH_X86, capstone.CS_MODE_32)
+md.detail=True
+code=data[ra0:ra0+n]
+hits=[]
+# quick byte-pattern prescan for disp32 0x768/0x76c/0x770 little-endian
+import re
+for target,label in [(0x768,"0x768"),(0x76c,"0x76c"),(0x770,"0x770")]:
+    pat=struct.pack("<I",target)
+    for m in re.finditer(re.escape(pat),code):
+        start=max(0,m.start()-8)
+        for ins in md.disasm(code[start:m.start()+12], va0+start):
+            if ins.op_str and label in ins.op_str and ("ptr [" in ins.op_str):
+                # writes: mov [reg+disp], src  OR fstp
+                if ins.mnemonic in ("mov","fstp","fst") and ins.op_str.index("[")<ins.op_str.index(","):
+                    hits.append((ins.address,f"{ins.mnemonic} {ins.op_str}"))
+                elif ins.mnemonic in ("fld","fcomp","fcom","mov") :
+                    pass
+seen=set()
+for a,t in sorted(hits):
+    if (a,t) not in seen:
+        seen.add((a,t)); print(f"0x{a:x}: {t}")