fix(channels): also pass path_hash_size on the echo-driven raw_packet rebuild

Earlier path_hash_mode fix updated the send-time build but the matching
edit to _refresh_raw_packet_if_drifted didn't make it into commit 10df846.
For channels where the secret isn't available at send time, guess_pkt_payload
stays None and raw_packet is created for the first time in this fallback
path (triggered when echo correlation matches via the channel-hash branch).
Without the path_hash_size argument the build defaulted to 1-byte hashes,
producing the same mixed-size badge the prior fix was meant to eliminate.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/device_manager.py

@@ -1260,6 +1260,7 @@ class DeviceManager:
             raw_packet = _build_grp_txt_raw_packet(
                 actual_pkt_payload,
                 scope_key_hex=scope['key_hex'] if scope else None,
+                path_hash_size=self.path_hash_size,
             )
             if raw_packet:
                 self.db.update_message_raw_packet(pe['msg_id'], raw_packet)