Add multi-SDR hardware support (LimeSDR, HackRF) and setup script

- Add SDR hardware abstraction layer (utils/sdr/) with support for:
  - RTL-SDR (existing, using native rtl_* tools)
  - LimeSDR (via SoapySDR)
  - HackRF (via SoapySDR)
- Add hardware type selector to UI with capabilities display
- Add automatic device detection across all supported hardware
- Add hardware-specific parameter validation (frequency/gain ranges)
- Add setup.sh script for automated dependency installation
- Update README with multi-SDR docs, installation guide, troubleshooting
- Add SoapySDR/LimeSDR/HackRF to dependency definitions
- Fix dump1090 detection for Homebrew on Apple Silicon Macs
- Remove defunct NOAA-15/18/19 satellites, add NOAA-21

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

utils/sdr/rtlsdr.py

@@ -0,0 +1,121 @@
+"""
+RTL-SDR command builder implementation.
+
+Uses native rtl_* tools (rtl_fm, rtl_433) and dump1090 for maximum compatibility
+with existing RTL-SDR installations. No SoapySDR dependency required.
+"""
+
+from typing import Optional
+
+from .base import CommandBuilder, SDRCapabilities, SDRDevice, SDRType
+
+
+class RTLSDRCommandBuilder(CommandBuilder):
+    """RTL-SDR command builder using native rtl_* tools."""
+
+    CAPABILITIES = SDRCapabilities(
+        sdr_type=SDRType.RTL_SDR,
+        freq_min_mhz=24.0,
+        freq_max_mhz=1766.0,
+        gain_min=0.0,
+        gain_max=49.6,
+        sample_rates=[250000, 1024000, 1800000, 2048000, 2400000],
+        supports_bias_t=True,
+        supports_ppm=True,
+        tx_capable=False
+    )
+
+    def build_fm_demod_command(
+        self,
+        device: SDRDevice,
+        frequency_mhz: float,
+        sample_rate: int = 22050,
+        gain: Optional[float] = None,
+        ppm: Optional[int] = None,
+        modulation: str = "fm",
+        squelch: Optional[int] = None
+    ) -> list[str]:
+        """
+        Build rtl_fm command for FM demodulation.
+
+        Used for pager decoding and iridium capture.
+        """
+        cmd = [
+            'rtl_fm',
+            '-d', str(device.index),
+            '-f', f'{frequency_mhz}M',
+            '-M', modulation,
+            '-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 squelch is not None and squelch > 0:
+            cmd.extend(['-l', str(squelch)])
+
+        # Output to stdout for piping
+        cmd.append('-')
+
+        return cmd
+
+    def build_adsb_command(
+        self,
+        device: SDRDevice,
+        gain: Optional[float] = None
+    ) -> list[str]:
+        """
+        Build dump1090 command for ADS-B decoding.
+
+        Uses dump1090 with network output for SBS data streaming.
+        """
+        cmd = [
+            'dump1090',
+            '--net',
+            '--device-index', str(device.index),
+            '--quiet'
+        ]
+
+        if gain is not None:
+            cmd.extend(['--gain', str(int(gain))])
+
+        return cmd
+
+    def build_ism_command(
+        self,
+        device: SDRDevice,
+        frequency_mhz: float = 433.92,
+        gain: Optional[float] = None,
+        ppm: Optional[int] = None
+    ) -> list[str]:
+        """
+        Build rtl_433 command for ISM band sensor decoding.
+
+        Outputs JSON for easy parsing.
+        """
+        cmd = [
+            'rtl_433',
+            '-d', str(device.index),
+            '-f', f'{frequency_mhz}M',
+            '-F', 'json'
+        ]
+
+        if gain is not None and gain > 0:
+            cmd.extend(['-g', str(int(gain))])
+
+        if ppm is not None and ppm != 0:
+            cmd.extend(['-p', str(ppm)])
+
+        return cmd
+
+    def get_capabilities(self) -> SDRCapabilities:
+        """Return RTL-SDR capabilities."""
+        return self.CAPABILITIES
+
+    @classmethod
+    def get_sdr_type(cls) -> SDRType:
+        """Return SDR type."""
+        return SDRType.RTL_SDR