Add packet_hash to bot kwargs. Closes #268.

app/path_utils.py

@@ -9,6 +9,7 @@ The path_len wire byte is packed as [hash_mode:2][hop_count:6]:
 Mode 3 (hash_size=4) is reserved and rejected.
 """
 
+import hashlib
 from collections.abc import Iterable
 from dataclasses import dataclass
 
@@ -289,3 +290,30 @@ def bucket_path_hash_widths(rows: Iterable) -> dict[str, int | float]:
         "double_byte_pct": (double_byte / total) * 100,
         "triple_byte_pct": (triple_byte / total) * 100,
     }
+
+
+def calculate_packet_hash(raw_bytes: bytes) -> str:
+    """Calculate packet hash matching MeshCore's Packet::calculatePacketHash().
+
+    Parses the packet structure to extract payload type and payload data,
+    then hashes: payload_type(1 byte) [+ path_len(2 bytes LE) for TRACE] + payload_data.
+    Returns first 16 hex characters (uppercase).
+    """
+    if not raw_bytes:
+        return "0" * 16
+
+    try:
+        envelope = parse_packet_envelope(raw_bytes)
+        if envelope is None:
+            return "0" * 16
+
+        hash_obj = hashlib.sha256()
+        hash_obj.update(bytes([envelope.payload_type]))
+        # TRACE hash uses the raw wire byte (not decoded hop count) to match firmware.
+        if envelope.payload_type == 9:  # PAYLOAD_TYPE_TRACE
+            hash_obj.update(envelope.path_byte.to_bytes(2, byteorder="little"))
+        hash_obj.update(envelope.payload)
+
+        return hash_obj.hexdigest()[:16].upper()
+    except Exception:
+        return "0" * 16