Lay the menu bar out the way N1MM lays it out, and fill in the Edit menu

The menu tree comes from N1MM's EntryWindow.Designer.cs: File, Edit, View,
Tools, Config, Window, with the items under the names N1MM gives them. The
window list moved out of View into Window; the call history file moved from
Config into File > Import. Ctrl+W, Ctrl+L and Ctrl+M now work, so the keys
printed in the menu are real. Two commands that had no menu item before:
the CW and SSB function key definitions, and the QTC setup area.

The rest of the Edit menu:

- Ctrl+N asks for a note and puts it in the comment of the contact in the
  boxes, or of the last logged contact when nothing is typed.
- Edit Current Contact opens the Edit Contact form over what is typed but
  not logged. Update hands the values back to the entry boxes.
- Ctrl+Q and Ctrl+A load a logged contact into the boxes and paint them
  pale yellow. Enter writes the change back, Esc puts back what was being
  typed, and stepping forward past the newest contact leaves quick edit.
- Ctrl+U raises the received serial, or a numeric exchange box when the
  contest has no serial.
- Ctrl+F shows the call being typed in the log window, then the next
  contact with that call.

RadioPosition is now OperatingPosition: it is the operator at one radio,
not a place on a band.

Looked at under Xvfb on a 3775-contact log: quick edit back and forward,
Esc, the note dialog, find, and Edit Current Contact putting a zone back
into the entry boxes.

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

src/Nonemm.App/Windows/LogWindow.axaml.cs

@@ -21,6 +21,7 @@ public sealed partial class LogWindow : RefreshableWindow
     private readonly AppSession session;
     private string builtFor = "";
     private string message = "";
+    private string finding = "";
 
     public LogWindow(AppSession session)
     {
@@ -105,6 +106,32 @@ public sealed partial class LogWindow : RefreshableWindow
     private static double MinimumFor(int characters) =>
         (characters * CharacterWidth) + CellPadding;
 
+    /// N1MM's Ctrl+F: shows the next contact with this call and selects it,
+    /// starting again from the top once the last one has been shown. Null when
+    /// the call is not in the log.
+    public Qso? FindNextCall(string call)
+    {
+        string wanted = call.Trim();
+        if (wanted.Length == 0 || Rows.ItemsSource is not IReadOnlyList<LogRow> rows)
+        {
+            return null;
+        }
+        int from = wanted.Equals(finding, StringComparison.OrdinalIgnoreCase) ? Rows.SelectedIndex + 1 : 0;
+        finding = wanted;
+        for (int step = 0; step < rows.Count; step++)
+        {
+            int at = (from + step) % rows.Count;
+            if (!rows[at].Qso.Call.Text.Equals(wanted, StringComparison.OrdinalIgnoreCase))
+            {
+                continue;
+            }
+            Rows.SelectedIndex = at;
+            Rows.ScrollIntoView(rows[at], null);
+            return rows[at].Qso;
+        }
+        return null;
+    }
+
     /// True when the edit was taken. A refused edit puts the reason in the
     /// summary line and the cell falls back to what it held before.
     private bool Edit(Qso qso, QsoField field, string text)