Chord: arm anchor on left double-click so dblclick -> chord flows

A double-click's second press arrives as MouseButtonDblClick, not a plain
press, so m_leftDownInView was never set and the still-held button could not
anchor a chord. Set the chord anchor on a left double-click inside the view
(bracket- or word-select), letting the user proceed directly from a
double-click into a left+middle (Cut) or left+right (Paste) chord without
releasing. All 5 ctest suites green.

docs/PLAN.md

@@ -150,6 +150,9 @@ Therefore the palette is replaced, not extended, and the replacement is built on
   (`characterAt`), scans with depth counting across line ends, and sets the
   selection. When no bracket is adjacent it falls through to Kate's default
   double-click (word select).
+- A left double-click leaves the button held, so it also arms the chord anchor:
+  the user can go straight from a double-click (bracket- or word-select) into a
+  left+middle / left+right chord without releasing.
 
 ### M5 — Command vocabulary + project model + switchers — NEXT
 - `:`-verb pack via `KTextEditor::Command`: `sort`, `align`, `json`, `b64`,

src/plugin/ollieplugin.cpp

@@ -494,15 +494,21 @@ bool OllieView::eventFilter(QObject *obj, QEvent *event)
 {
     // Bracket-pair selection: double-clicking next to a bracket selects the
     // text between the matching pair (multi-line). Falls through to Kate's
-    // default double-click (word select) when no bracket is adjacent.
+    // default double-click (word select) when no bracket is adjacent. The
+    // second click of a double-click arrives as DblClick (not a plain press)
+    // and leaves the left button held, so it also arms the chord anchor —
+    // letting the user go straight from a double-click into a mouse chord.
     if (event->type() == QEvent::MouseButtonDblClick) {
         auto *mev = static_cast<QMouseEvent *>(event);
         if (mev->button() == Qt::LeftButton) {
             KTextEditor::View *v = m_mainWindow->activeView();
             auto *w = qobject_cast<QWidget *>(obj);
-            if (v && w && v->isAncestorOf(w)
-                && selectBracketPairAt(v, mev->globalPosition().toPoint())) {
-                return true; // handled: suppress default word-select
+            const bool inView = v && w && v->isAncestorOf(w);
+            if (inView) {
+                m_leftDownInView = true; // held after the dblclick: chord anchor
+                if (selectBracketPairAt(v, mev->globalPosition().toPoint())) {
+                    return true; // handled: suppress default word-select
+                }
             }
         }
     }