gui: Options, Scheduler, Speed Limiter, Batch, Grabber, and the tray icon

Continues the build order past the Add-URL/File-Info/Progress dialog flow.

- OptionsDialog: General/Save To/Connection/Downloads/Proxy/Sounds tabs, every
  control bound to a real settings.* key (contracts/schema/types/Settings.
  schema.json). The spec's File Types and Site Logins tabs have no settings.*
  backing (categories go through category.upsert, credentials through the
  Secret Service) so they don't exist here — a tab either binds to a real key
  or isn't shipped. diffChanged() sends only what actually changed, matching
  settings.set's "changed[] names exactly what took effect" contract.
- SchedulerDialog: per-queue schedule (schedule.get/set) plus maxConcurrent/
  onComplete (queue.upsert), Start Now/Stop. Queue.schema.json already carries
  the schedule so queue.list alone seeds the window.
- SpeedLimiterDialog: the live global limiter (limiter.get/set) — a different
  thing from Options' downloads.speedLimit* default. buildParams() enforces
  the schema's "0 with enabled true must not be offered".
- BatchDialog: clipboard-blob and {start..end}-wildcard tabs sharing one
  category/queue/start-mode footer into download.addBatch.
- GrabberWizard: 4-step QWizard (project label -> start URL/depth/filters ->
  file-type filter -> review), grabber.start feeding a poll+event.grabber.
  progress-driven review page, Finish = grabber.harvest for the checked files.
- TrayIcon: active-count tooltip, Show/Add URL/Pause All/Resume All/Speed
  Limiter submenu/Quit. Quit only closes the GUI — there is no RPC to stop
  veloxd itself, filed as a new gap in daemon-requests-m1.md. MainWindow now
  also hides to tray instead of closing when general.minimizeToTray is set.

Every dialog's non-widget logic (diffChanged, buildSchedule, buildParams,
parseUrlBlob/expandWildcard/buildAddBatchParams, buildFileTypes/
buildStartParams/buildHarvestParams) is a static pure function with its own
test, same shape as FileInfoDialog::buildSpec from the previous round.

Verified end-to-end against a running mockd under ASan+UBSan: all five
surfaces render real data (settings.get values, queue.list's two seeded
queues, limiter.get, a live grabber.start/status crawl returning 3 files) with
no sanitizer reports. gui-check (non-ASan) and dev (ASan+UBSan) presets both
build the whole repo clean; all gui-labeled ctest targets pass.

Co-Authored-By: Claude Sonnet 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01NSCdCWFXBTSBBK3MzWtJiC

gui/tests/tst_optionsdialog.cpp

@@ -0,0 +1,54 @@
+// OptionsDialog::diffChanged unit tests. Lane GUI.
+//
+// Red when a key that didn't actually change starts getting resent to settings.set (it
+// would still work, but it defeats the fixture's "changed[] names exactly what took
+// effect" contract and spams event.settings.changed with noise), or a key present in
+// `current` but absent from `original` stops being treated as changed.
+
+#include <QJsonObject>
+#include <QtTest>
+
+#include "dialogs/OptionsDialog.hpp"
+
+using velox::gui::OptionsDialog;
+
+class TstOptionsDialog : public QObject {
+    Q_OBJECT
+
+  private slots:
+    void identicalValuesProduceNoDiff();
+    void onlyChangedKeysAreReturned();
+    void keyAbsentFromOriginalCountsAsChanged();
+    void allKeysAreNonEmptyAndUnique();
+};
+
+void TstOptionsDialog::identicalValuesProduceNoDiff() {
+    const QJsonObject original{{"connection.timeoutSec", 30}, {"proxy.mode", "system"}};
+    const QJsonObject current = original;
+    QVERIFY(OptionsDialog::diffChanged(original, current).isEmpty());
+}
+
+void TstOptionsDialog::onlyChangedKeysAreReturned() {
+    const QJsonObject original{{"connection.timeoutSec", 30}, {"proxy.mode", "system"}};
+    const QJsonObject current{{"connection.timeoutSec", 60}, {"proxy.mode", "system"}};
+    const QJsonObject changed = OptionsDialog::diffChanged(original, current);
+    QCOMPARE(changed.size(), 1);
+    QCOMPARE(changed.value("connection.timeoutSec").toInt(), 60);
+}
+
+void TstOptionsDialog::keyAbsentFromOriginalCountsAsChanged() {
+    const QJsonObject original{{"proxy.mode", "system"}};
+    const QJsonObject current{{"proxy.mode", "system"}, {"proxy.port", 1080}};
+    const QJsonObject changed = OptionsDialog::diffChanged(original, current);
+    QCOMPARE(changed.size(), 1);
+    QVERIFY(changed.contains("proxy.port"));
+}
+
+void TstOptionsDialog::allKeysAreNonEmptyAndUnique() {
+    const QStringList keys = OptionsDialog::allKeys();
+    QVERIFY(!keys.isEmpty());
+    QCOMPARE(QSet<QString>(keys.begin(), keys.end()).size(), keys.size());
+}
+
+QTEST_MAIN(TstOptionsDialog)
+#include "tst_optionsdialog.moc"