Remove waterfall from all modes except listening post

Reverts IQ pipeline and removes syncWaterfallToFrequency calls from
pager, sensor, rtlamr, DMR, SSTV, and SSTV general modes. Waterfall
is now exclusive to listening post mode.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

utils/sdr/rtlsdr.py

@@ -197,43 +197,6 @@ class RTLSDRCommandBuilder(CommandBuilder):
 
         return cmd
 
-    def build_raw_capture_command(
-        self,
-        device: SDRDevice,
-        frequency_mhz: float,
-        sample_rate: int,
-        gain: Optional[float] = None,
-        ppm: Optional[int] = None,
-        bias_t: bool = False
-    ) -> list[str]:
-        """
-        Build rtl_sdr command for raw IQ capture.
-
-        Outputs raw uint8 IQ to stdout for processing by IQ pipelines.
-        """
-        rtl_sdr_path = get_tool_path('rtl_sdr') or 'rtl_sdr'
-        freq_hz = int(frequency_mhz * 1e6)
-        cmd = [
-            rtl_sdr_path,
-            '-d', self._get_device_arg(device),
-            '-f', str(freq_hz),
-            '-s', str(sample_rate),
-        ]
-
-        if gain is not None and gain > 0:
-            cmd.extend(['-g', str(gain)])
-
-        if ppm is not None and ppm != 0:
-            cmd.extend(['-p', str(ppm)])
-
-        if bias_t:
-            cmd.extend(['-T'])
-
-        # Output to stdout
-        cmd.append('-')
-
-        return cmd
-
     def build_ais_command(
         self,
         device: SDRDevice,