feat: upgrade FFE1 command to 34 bytes with control byte

Per 协议简述(3): Byte33 is now control instruction (0=IDLE, 1=scan,
2=treat), Byte34 is XOR checksum. Backward compat with 33-byte
read-back preserved. All command sites updated with correct control:
- auto-scan: control=0x01 (scan mode)
- treatment-setup: control=0x02 (treat mode)
- stopTreatment: control=0x00 (IDLE)

miniprogram/services/ble/index.js

@@ -15,6 +15,7 @@ module.exports = {
   WAVELENGTH: protocol.WAVELENGTH,
   TREAT_MODE: protocol.TREAT_MODE,
   REGION: protocol.REGION,
+  CONTROL: protocol.CONTROL,
   DEVICE_ERR: protocol.DEVICE_ERR,
 
   // Connection
@@ -41,6 +42,7 @@ module.exports = {
   PROTOCOL_MODE: protocol.PROTOCOL_MODE,
   buildFrame: protocol.buildFrame,
   parseFrame: protocol.parseFrame,
+  buildVendorCommand: protocol.buildVendorCommand,
   buildVendorCommand33: protocol.buildVendorCommand33,
   parseVendorStatus: protocol.parseVendorStatus,
   parseStatusReport: protocol.parseStatusReport,