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, 1 insertions, 1 deletions

diff --git a/ui/windows/devices_window.py b/ui/windows/devices_window.py
index 5919938..ac9d13c 100644
--- a/ui/windows/devices_window.py
+++ b/ui/windows/devices_window.py
@@ -144,7 +144,7 @@ class ChannelsTab(QWidget):
         self._table.setObjectName("channelTable")
         self._table.setColumnCount(7)
         self._table.setHorizontalHeaderLabels(
-            ["Device", "Channel ID", "On", "Name", "Unit", "Min", "Max"]
+            ["Device", "Signal ID", "On", "Name", "Unit", "Min", "Max"]
         )
         hdr = self._table.horizontalHeader()
         hdr.setSectionResizeMode(self._C_NAME,    QHeaderView.ResizeMode.Stretch)