docs(logging): note the Info-rule asymmetry and the test's no-op save path (aethersdr#4588 review)

Comment-only. The applyFilterRules() comment now states that no blanket
aether.*.info=false is emitted, so the seven QtDebugMsg/QtInfoMsg-declared
categories keep their Info regardless of the toggle. The test's settings
sandbox is kept as defense-in-depth and marked as an intentional no-op
(AppSettings refuses to save before a successful load).

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

Author: skerker

src/core/LogManager.cpp

@@ -142,6 +142,10 @@ void LogManager::applyFilterRules()
             // Most categories declare a QtWarningMsg threshold, which gates
             // Info as well as Debug — without an .info rule their qCInfo
             // lines can never emit under any runtime configuration (#4419).
+            // Note the asymmetry: no blanket aether.*.info=false is emitted
+            // (it would newly silence the QtDebugMsg/QtInfoMsg-declared
+            // categories), so for those the toggle governs Debug only and
+            // their Info stays visible regardless.
             rules << QString("%1.info=true").arg(c.id);
         }
     }

tests/log_manager_filter_rules_test.cpp

@@ -46,6 +46,11 @@ void captureHandler(QtMsgType type, const QMessageLogContext& ctx, const QString
 
 int main(int argc, char** argv)
 {
+    // Defense-in-depth only: the save path in setEnabled()/setAllEnabled() is
+    // intentionally a no-op here — AppSettings refuses to save before a
+    // successful load(), which this test never performs (the "refusing to
+    // save" warnings in the output are expected). The sandbox guards against
+    // that refusal ever changing.
     QTemporaryDir fakeHome(QDir::tempPath() + "/aether-logmanager-filter-test-XXXXXX");
     if (!fakeHome.isValid()) {
         std::printf("[FAIL] create temporary home\n");