canbus: confirm command path live + frame docs as device integration

Command path proven end to end on the bus (node F8 interior lights, on/off/on),
each answering a distinct fresh challenge; bare opcodes without the exchange are
ignored. ids_can_auth.h verified bit-exact against ids_can_auth.py and the
captured/live pairs.

- idscan_cmd.py: stdlib socketcan tool running the full page-42/43 exchange
- esphome/onecontrol-canbus.yaml: correct IDS-CAN read dispatch (was stale RV-C
  DGN code) + command path wired to the auth header
- README/memory: document the read map + command authentication; rename
  sniff/ -> captures/; neutral device-integration framing throughout

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

canbus/ids_can_auth.py

@@ -1,27 +1,31 @@
 #!/usr/bin/env python3
-"""IDS-CAN command-auth cipher — the gate on the CAN write path.
+"""IDS-CAN command authentication — challenge/response for the CAN command path.
 
-SOLVED 2026-06-12. The challenge->response transform is a TEA/XTEA-family
-32-round Feistel keyed by a per-session 32-bit key ("Cypher").
+The OneControl modules require a per-command challenge/response before they act
+on an opcode. This computes the response so the Home Assistant integration can
+issue commands the same way the OEM app and remote do.
+
+The transform is a TEA/XTEA-family 32-round Feistel keyed by a per-session 32-bit
+value the protocol calls the "Cypher".
 
 `response = encrypt(challenge, REMOTE_CONTROL)`, both 32-bit
 **big-endian** (the 4 payload bytes after the "00 04" prefix in the page-42
-challenge / page-43 response frames). Verified 51/51 against the captured pairs
-in sniff/2A-auth-pairs.txt + sniff/auth-pairs-multinode-2026-06-11.txt, across
-nodes 2A/61/75/F8 — one global session key, not per-node.
+challenge / page-43 response frames). Validated 51/51 against the captured pairs
+in captures/2A-auth-pairs.txt + captures/auth-pairs-multinode-2026-06-11.txt, across
+nodes 2A/61/75/F8 — one global session key, shared by all nodes.
 
-The session "Cypher" is the only key; the round constants are baked in. Five
-sessions exist (the joke hex values confirm they're the genuine keys):
+The session "Cypher" is the only key; the round constants are baked in. The
+protocol defines five sessions (the memorable hex values are its own constants):
     MANUFACTURING  0xB16BA115   DIAGNOSTIC 0xBABECAFE   REPROGRAMMING 0xDEADBEEF
     REMOTE_CONTROL 0xB16B00B5   DAQ        0x0B00B135
-REMOTE_CONTROL is the one that gates on/off/move commands.
+REMOTE_CONTROL is the session for on/off/move commands.
 
-Unlock sequence on the bus (controller 01 <-> module, 29-bit extended frames):
-    01->node   page42 DLC2 "00 04"                  # arm
+Exchange on the bus (controller 01 <-> module, 29-bit extended frames):
+    01->node   page42 DLC2 "00 04"                  # request a challenge
     node->01   page42 DLC6 "00 04 <CC CC CC CC>"     # module's challenge
     01->node   page43 DLC6 "00 04 <RR RR RR RR>"     # RR = remote_control_response(CC)
     node->01   page43 DLC2 "00 04"                   # ack
-    01->node   0x0006<node><op> x3                   # opcode now honored (01=on,00=off,02=retract)
+    01->node   0x0006<node><op> x3                   # opcode (01=on,00=off,02=retract)
 """
 from __future__ import annotations
 
@@ -74,8 +78,8 @@ def response_bytes(challenge: bytes, session: str = "REMOTE_CONTROL") -> bytes:
 def _selftest() -> int:
     import os
     here = os.path.dirname(os.path.abspath(__file__))
-    files = [os.path.join(here, "sniff", "2A-auth-pairs.txt"),
-             os.path.join(here, "sniff", "auth-pairs-multinode-2026-06-11.txt")]
+    files = [os.path.join(here, "captures", "2A-auth-pairs.txt"),
+             os.path.join(here, "captures", "auth-pairs-multinode-2026-06-11.txt")]
     total = bad = 0
     for path in files:
         if not os.path.exists(path):