Add bias_t parameter to build_ism_command()

Same fix as build_fm_demod_command() - the parameter was being
passed but not defined in the method signatures.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

utils/sdr/rtlsdr.py

@@ -115,7 +115,8 @@ class RTLSDRCommandBuilder(CommandBuilder):
         device: SDRDevice,
         frequency_mhz: float = 433.92,
         gain: Optional[float] = None,
-        ppm: Optional[int] = None
+        ppm: Optional[int] = None,
+        bias_t: bool = False
     ) -> list[str]:
         """
         Build rtl_433 command for ISM band sensor decoding.
@@ -135,6 +136,9 @@ class RTLSDRCommandBuilder(CommandBuilder):
         if ppm is not None and ppm != 0:
             cmd.extend(['-p', str(ppm)])
 
+        if bias_t:
+            cmd.extend(['-T'])
+
         return cmd
 
     def get_capabilities(self) -> SDRCapabilities: