Parse Framed Sensor Data Packets

Problem

Given a list of byte values stream representing data received over a serial interface, parse all valid sensor packets and return their decoded fields. Each packet has the format [0xAA, length, sensor_id, payload..., checksum], where length is the number of bytes in [sensor_id, payload...], and checksum equals (length + sensor_id + sum(payload)) % 256. Ignore noise bytes before a header, skip malformed packets, and continue scanning for the next valid packet.

Constraints

• 1 <= len(stream) <= 10^5
• 0 <= stream[i] <= 255
• 1 <= length <= 255 for a valid packet
• A valid packet must contain exactly length + 3 bytes including header, length, and checksum