Channels/Signals UX: rename labels, calibration section, splitter, sig# IDs

Naming conventions:
- Devices window: "Channel ID" column → "Signal ID"
- Serial device auto-gen IDs: CH# → sig# (generic, SCPI, Modbus fallbacks)
- Channels window physical section: "Physical Channels" → "Signals"
- Channels window virtual section: "Virtual Channels" → "Channels"
- "Add Virtual" button → "Add Channel"
- New derived channel default name: "Virtual Channel #" → "Channel #"

Signals panel (ChannelPipelineBlock):
- Remove Calibrate header button; add inline Calibration section in body
- Remove Math section (Derivative/Integral) entirely
- scale_offset excluded from filter dropdown; routed to Calibration section
- Existing pipelines: scale_offset loads into Calibration, math filters dropped
- _FILTER_KEYS excludes derivative, integral, scale_offset

Splitter default position:
- Left (Signals) pane initialised to minimum content width via QTimer.singleShot
- setStretchFactor(0,0) / (1,1): left stays narrow, right grows on resize

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

1 files changed, 5 insertions, 5 deletions

diff --git a/devices/serial_device.py b/devices/serial_device.py
index c3ce65f..458aec8 100644
--- a/devices/serial_device.py
+++ b/devices/serial_device.py
@@ -241,7 +241,7 @@ class SerialDevice(BaseDevice):
     def _build_channel_configs(self) -> List[ChannelConfig]:
         fmt = self._fmt
         if fmt in _GENERIC_FORMATS:
-            names = self._chan_names or [f"CH{i}" for i in range(self._num_channels)]
+            names = self._chan_names or [f"sig{i}" for i in range(self._num_channels)]
             _units = self._units or [""] * len(names)
             return [
                 ChannelConfig(
@@ -599,8 +599,8 @@ class _SCPIPanel(QWidget):
         row = self._table.rowCount()
         self._table.insertRow(row)
         n = row
-        self._table.setItem(row, 0, QTableWidgetItem(sc["channel_id"]         if sc else f"CH{n}"))
-        self._table.setItem(row, 1, QTableWidgetItem(sc.get("name", f"CH{n}") if sc else f"CH{n}"))
+        self._table.setItem(row, 0, QTableWidgetItem(sc["channel_id"]           if sc else f"sig{n}"))
+        self._table.setItem(row, 1, QTableWidgetItem(sc.get("name", f"sig{n}") if sc else f"sig{n}"))
         self._table.setItem(row, 2, QTableWidgetItem(sc.get("query", "MEAS:VOLT?") if sc else "MEAS:VOLT?"))
         self._table.setItem(row, 3, QTableWidgetItem(sc.get("unit", "")       if sc else ""))
         self._table.setItem(row, 4, QTableWidgetItem(str(sc.get("scale", 1.0)) if sc else "1.0"))
@@ -619,8 +619,8 @@ class _SCPIPanel(QWidget):
             except ValueError:
                 scale = 1.0
             result.append({
-                "channel_id": cell(0) or f"CH{row}",
-                "name":       cell(1) or f"CH{row}",
+                "channel_id": cell(0) or f"sig{row}",
+                "name":       cell(1) or f"sig{row}",
                 "query":      cell(2),
                 "unit":       cell(3),
                 "scale":      scale,