refactor: revert replay code, preserve non-replay fixes

Revert raw IQ replay (commits 2cb56e8..6095893) to prepare
for unified SoftwareFPGA replay architecture.

Preserved: C-locale spinboxes, AGC chart label, demo/radar
mutual exclusion.

Delete v7/raw_iq_replay.py
Restore workers.py, processing.py, models.py, __init__.py, test_v7.py

9_Firmware/9_3_GUI/v7/models.py

@@ -96,47 +96,6 @@ class RadarTarget:
         return asdict(self)
 
 
-@dataclass
-class WaveformConfig:
-    """FMCW waveform parameters for bin-to-physical-unit conversion.
-
-    Defaults are for the ADI CN0566 phaser (10 GHz, 500 MHz BW, 300 µs chirp,
-    4 MSPS ADC).  For the PLFM FPGA waveform the values differ — but the FPGA
-    pipeline hardcodes its own bin widths, so this config is only used for
-    Raw IQ Replay (host-side FFT processing).
-    """
-    sample_rate_hz: float = 4e6         # ADC sample rate (Hz)
-    bandwidth_hz: float = 500e6         # Chirp bandwidth (Hz)
-    chirp_duration_s: float = 300e-6    # Chirp sweep time (s)
-    center_freq_hz: float = 10e9        # Carrier frequency (Hz)
-
-    # --- derived quantities (need n_samples, n_chirps from file) ---
-
-    def range_resolution(self, n_samples: int) -> float:
-        """Metres per range bin for an N-point range FFT.
-
-        range_per_bin = c · fs / (2 · N · slope)
-        where slope = BW / T_chirp.
-        """
-        c = 299_792_458.0
-        slope = self.bandwidth_hz / self.chirp_duration_s
-        return c * self.sample_rate_hz / (2.0 * n_samples * slope)
-
-    def velocity_resolution(self, n_samples: int, n_chirps: int) -> float:
-        """m/s per Doppler bin for an M-chirp Doppler FFT.
-
-        vel_per_bin = λ · fs / (2 · N · M)
-        where λ = c / fc, N = n_samples (PRI = N/fs), M = n_chirps.
-        """
-        c = 299_792_458.0
-        wavelength = c / self.center_freq_hz
-        return wavelength * self.sample_rate_hz / (2.0 * n_samples * n_chirps)
-
-    def max_range(self, n_range_bins: int, n_samples: int) -> float:
-        """Maximum unambiguous range for the given bin count."""
-        return self.range_resolution(n_samples) * n_range_bins
-
-
 @dataclass
 class RadarSettings:
     """Radar system display/map configuration.