keymap: register complete_query bound to Ctrl+Space

KeyMap::defaultBindings() is the single source of truth for shortcuts:
the menus, the shortcut reference dialog and loadDefaults() all read it,
so registering here makes the binding appear in the reference and stay
rebindable from [keys] without any of them disagreeing.

Ctrl+Space is a modifier plus a named key, so it sidesteps the bare
capital trap in normalizeSequence() and needs no Shift on any layout.
Verified it parses to a single non-empty combination that round-trips to
"Ctrl+Space", and it collides with no existing default.

Note test_mainwindow now fails its everyKnownActionIsRegistered()
assertion: MainWindow does not yet implement complete_query. That wiring
is a separate task, and the assertion firing is the intended signal.

1 files changed, 8 insertions, 0 deletions

diff --git a/tests/test_keymap.cpp b/tests/test_keymap.cpp
index 0fb4f57..8f6a6af 100644
--- a/tests/test_keymap.cpp
+++ b/tests/test_keymap.cpp
@@ -37,8 +37,16 @@ private slots:
     void defaultsDoNotCollide();
     void everyDefaultIsAKnownAction();
     void everyDefaultParses();
+    void completeQueryIsBoundByDefault();
 };
 
+void TestKeyMap::completeQueryIsBoundByDefault()
+{
+    QVERIFY(KeyMap::knownActions().contains(QStringLiteral("complete_query")));
+    QCOMPARE(KeyMap::defaultSequenceFor(QStringLiteral("complete_query")),
+             QKeySequence(QStringLiteral("Ctrl+Space")));
+}
+
 void TestKeyMap::everyDefaultParses()
 {
     // A default that does not parse is a dead binding, the failure mode