Persist dock layout to profiles; dedupe port names; Channels-tab Create button

- Fix duplicated device names ("FT231X USB UART - FT231X USB UART (...)")
  — pyserial on Linux often reports the same udev model string twice for
  cheap FTDI/CH340-style adapters. Collapse it at the list_ports() source
  so every consumer (device auto-name, port picker) benefits.

- Save Control Panel / Namespace dock area, floating geometry, visibility,
  size and order to .labui profiles via QMainWindow.saveState()/
  restoreState(), round-tripped through the existing Profile.settings
  passthrough (self._settings) — no profile schema change needed.

- Channels tab: replace the per-row Signal ⊕ button (and its pinned/
  frozen-column overlay) with a single "Create Channel" button below the
  Namespace panel. Select one or more Signal/Channel rows (multi-select
  now supported) and click it — selected rows become the new Channel's
  sources, or an empty Channel is created if nothing's selected. Fixes a
  bug in the process: the multi/zero-source path defaulted to
  kind="expression" with no expression text, which fails to compile and
  silently dropped the channel; use kind="none" instead, which the user
  then edits in the Channels pane.

  NamespacePanel itself (ui/namespace_panel.py) goes back to a plain
  read-only reference widget — the create-channel button and its logic
  live entirely in ConfigWindow (config_window.py), so the shared
  dockable Namespace panel on the main window is unaffected.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

1 files changed, 78 insertions, 26 deletions

diff --git a/ui/windows/config_window.py b/ui/windows/config_window.py
index 7ec0355..9b864bf 100644
--- a/ui/windows/config_window.py
+++ b/ui/windows/config_window.py
@@ -8,12 +8,13 @@ Devices tab layout (2 columns):
   Right — signal table (Device / Signal ID / Dir / On / Label / Unit / Min / Max)
 
 Channels tab layout (2 columns):
-  Left  — Namespace browser (Signals / Channels / vars). Mostly a read-only
-           reference, with one exception: each Signal row has a ⊕ button to
-           create a passthrough Channel from it directly — the quick "make
-           this Signal a Channel" path. See ui/namespace_panel.py — only
-           this instance opts into that button (on_create_channel), not the
-           read-only dockable Namespace panel on the main window.
+  Left  — Namespace browser (Signals / Channels / vars, ui/namespace_panel.py
+           — plain read-only reference, reused as-is for the dockable
+           Namespace panel on the main window too) plus a "Create Channel"
+           button below it, local to this tab only: uses whichever rows are
+           selected (multi-select) as the new Channel's sources, or creates
+           an empty Channel if nothing's selected. See _on_create_channel_
+           clicked().
   Right — derived / virtual channels — operations (filters/calibration/math/script)
            are configured per Channel here, not on the Signals side.
 """
@@ -471,10 +472,20 @@ class ConfigWindow(QWidget):
         ns_div = QFrame(); ns_div.setFrameShape(QFrame.Shape.HLine)
         ns_div.setObjectName("devWindowDivider"); ns_l.addWidget(ns_div)
 
-        self._namespace_panel = NamespacePanel(self.registry, self.processor,
-                                                on_create_channel=self._on_create_channel)
+        self._namespace_panel = NamespacePanel(self.registry, self.processor)
         self.processor.processed_data.connect(self._namespace_panel.on_processed_data)
         ns_l.addWidget(self._namespace_panel, 1)
+
+        ns_create_bar = QWidget(); ns_create_bar.setObjectName("cfgGlobalBar")
+        nc_lay = QHBoxLayout(ns_create_bar); nc_lay.setContentsMargins(10, 7, 10, 7); nc_lay.setSpacing(6)
+        nc_lay.addStretch()
+        create_btn = QPushButton("＋ Create Channel"); create_btn.setObjectName("addTraceBtn")
+        create_btn.setToolTip("Selected rows become the new Channel's sources — "
+                               "none selected creates an empty Channel")
+        create_btn.clicked.connect(self._on_create_channel_clicked)
+        nc_lay.addWidget(create_btn)
+        ns_l.addWidget(ns_create_bar)
+
         splitter.addWidget(ns_w)
 
         # Right: derived channels only
@@ -489,29 +500,70 @@ class ConfigWindow(QWidget):
             inner_splitters[0].widget(0).setVisible(False)
         splitter.addWidget(self._pipeline_tab)
 
-        # Channels side larger by default
-        splitter.setStretchFactor(0, 1)
-        splitter.setStretchFactor(1, 3)
+        # Namespace starts at its content-driven natural width (see
+        # NamespacePanel.natural_width() — a query only, not an enforced
+        # minimum: a hard setMinimumWidth() here used to fight QMainWindow's
+        # dock layout when this same NamespacePanel class is also docked
+        # stacked/tabbed with the Control Panel dock, ui/main_window.py).
+        # Stretch factor 0 means Channels absorbs window-resize growth;
+        # dragging the divider narrower than natural_width() just lets
+        # Source etc. scroll — the user's call.
+        splitter.setStretchFactor(0, 0)
+        splitter.setStretchFactor(1, 1)
+
+        def _init_ns_split():
+            ns_w0 = self._namespace_panel.natural_width()
+            total = splitter.width()
+            splitter.setSizes([ns_w0, max(1, total - ns_w0)])
+
+        QTimer.singleShot(0, _init_ns_split)
 
         self.tabs.addTab(w, "  Channels  ")
 
-    def _on_create_channel(self, dev_id: str, ch_id: str, ch_name: str, unit: str, color: str):
-        """Create a passthrough Channel (kind="none") from this Signal,
-        named after it — the "1 Signal -> 1 Channel" quick path, triggered
-        from the ⊕ button on a Signal row in the Channels tab's Namespace
-        panel (ui/namespace_panel.py). No-ops if a passthrough Channel for
-        this exact Signal already exists."""
-        existing = self.processor.get_derived()
-        for dc in existing:
-            if dc.kind == "none" and dc.sources == [(dev_id, ch_id)]:
-                return
+    def _on_create_channel_clicked(self):
+        """Create Channel button below the Channels tab's Namespace panel —
+        local to this tab (see module docstring). Uses whatever Signal/
+        Channel rows are currently selected (ui/namespace_panel.py::
+        NamespacePanel.selected_references(), multi-select) as the new
+        Channel's sources; none selected creates an empty Channel."""
+        refs = self._namespace_panel.selected_references()
+        existing       = self.processor.get_derived()
         existing_names = {d.name for d in existing}
         existing_ids   = {d.channel_id for d in existing}
-        name = _dedupe_name(ch_name, existing_names)
-        channel_id = _slug_id(name, existing_ids)
-        dc = Channel(channel_id=channel_id, name=name, kind="none",
-                      sources=[(dev_id, ch_id)], source_names=[ch_name],
-                      unit=unit, color=color or "#00d4ff")
+
+        if len(refs) == 1:
+            # Exactly one Signal/Channel selected — the "1 -> 1 passthrough"
+            # quick path. No-ops if one already exists for this exact source.
+            dev_id, ch_id, ch_name, unit, color = refs[0]
+            for dc in existing:
+                if dc.kind == "none" and dc.sources == [(dev_id, ch_id)]:
+                    return
+            name = _dedupe_name(ch_name, existing_names)
+            channel_id = _slug_id(name, existing_ids)
+            dc = Channel(channel_id=channel_id, name=name, kind="none",
+                          sources=[(dev_id, ch_id)], source_names=[ch_name],
+                          unit=unit, color=color or "#00d4ff")
+        else:
+            # Zero selected -> empty Channel, same naming convention
+            # PipelineTab._add_virtual() uses for one. Two+ selected -> one
+            # Channel sourced from all of them. kind="none" here (not
+            # "expression") because it's the only kind that compiles
+            # trivially with no expression/script text set yet — Channel.
+            # compile() does `compile(f"__result__ = {self.expression}")`
+            # for "expression", which is a SyntaxError on the default blank
+            # string, so processor.add_derived() below would silently fail
+            # and never add the channel. _add_virtual() gets away with
+            # defaulting to "expression" because it never calls
+            # add_derived() itself — it hands the Channel to the editor and
+            # waits for the user's own Apply. This path calls add_derived()
+            # immediately, so it needs a kind that survives that. The user
+            # picks the real kind/expression afterward in the editor.
+            name = _dedupe_name(f"Channel {len(existing) + 1}", existing_names)
+            channel_id = _slug_id(name, existing_ids)
+            dc = Channel(channel_id=channel_id, name=name, kind="none",
+                          sources=[(d, c) for d, c, *_ in refs],
+                          source_names=[n for _, _, n, _, _ in refs])
+
         err = self.processor.add_derived(dc)
         if err is None:
             self._pipeline_tab.refresh_derived()