Take a clicked word into the box the cursor is in

GrabIntoFocused puts text in whichever box has the cursor, whatever kind of
value that box normally holds. It is what N1MM's digital window does on
Ctrl+click, for the exchange element the contest has no box for.

The entry window also says when a CQ has gone out, which the digital window
needs to clear its grab list on: a run that starts again brings new callers.

GrabList.N1mmDepth is the ten calls N1MM's grab window holds.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RoGtneMQaz4M9w7Kk49AVD

src/Nonemm.Session/GrabList.cs

@@ -24,6 +24,9 @@ public enum GrabFilter
 /// calls nothing has ever heard of.
 public sealed class GrabList
 {
+    /// How many calls N1MM's grab window holds.
+    public const int N1mmDepth = 10;
+
     private readonly List<string> calls = [];
 
     public GrabList(int capacity = 30)