Make Channel the single source of truth for a reading's name

Device tab stays hardware-only (pins, wiring, may vary per workstation);
the Channels window owns the profile-facing identity. Concretely:

- Fix a real regression: SerialDevice generic-format Apply & Reconnect
  nulled out custom channel_names/units every time (no fallback, unlike
  every other optional field in reconfigure()), silently reverting to
  sig0/sig1/... ids.
- Plot legend now live-tracks the current Signal/Channel name instead of
  freezing tr.label at add-time, so a rename shows up without re-adding
  the trace.
- Add an inline quick-reconnect (combo + button, pre-selects the actual
  current source) directly on each Channel block in the Channels window,
  for the common single-source case — rewiring hardware no longer means
  touching every Plot/pipeline that referenced it.
- Collapse the Channel ID field behind an "ID ▸" advanced toggle;
  channel_id is already auto-derived from the name (_slug_id) and rarely
  needs to be seen.
- Devices tab's Signal "Name" column relabeled "Label" with a tooltip —
  de-emphasized now that Channel name is the real identity.
- Move "create a Channel from this Signal" from a column on the Devices
  tab's signal table to a ⊕ button on each Signal row in the Channels
  tab's Namespace panel — the action now lives where the identity is
  created, not on the hardware tab. Only that instance opts in
  (on_create_channel); the read-only Namespace dock on the main window
  is unaffected.
- Floor the Namespace panel's width at its columns' natural size so
  dragging the Channels-tab splitter narrower can't push the ⊕ column
  behind the horizontal scrollbar.
- Breadcrumb log when a profile-saved Signal override can't be applied
  because the signal_id no longer exists.

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

1 files changed, 7 insertions, 1 deletions

diff --git a/ui/windows/devices_window.py b/ui/windows/devices_window.py
index 5d47681..15549f1 100644
--- a/ui/windows/devices_window.py
+++ b/ui/windows/devices_window.py
@@ -157,8 +157,14 @@ class SignalsTab(QWidget):
         self._table.setObjectName("channelTable")
         self._table.setColumnCount(6)
         self._table.setHorizontalHeaderLabels(
-            ["Device", "On", "Name", "Unit", "Min", "Max"]
+            ["Device", "On", "Label", "Unit", "Min", "Max"]
         )
+        name_hdr_item = self._table.horizontalHeaderItem(self._C_NAME)
+        if name_hdr_item is not None:
+            name_hdr_item.setToolTip(
+                "Technical label only — for the profile-facing name, create a Channel "
+                "in the Channels window."
+            )
         hdr = self._table.horizontalHeader()
         hdr.setSectionResizeMode(self._C_NAME,    QHeaderView.ResizeMode.Stretch)
         hdr.setSectionResizeMode(self._C_DEVICE,  QHeaderView.ResizeMode.ResizeToContents)