Phase 5 sub-commit 1: DevConsole + child-output capture + Ctrl+` toggle

BackendConnection now captures the bundled FrankenPHP child's merged
stdout+stderr into a 500-line ring buffer, mirrors each line through
qCInfo(lcBundled) so terminal users still see logs, and exposes
childLogTail() / childLogLine for QML.

DevConsole.qml is an opt-in monospaced viewer with auto-scroll + clear
that the skeleton and the todo example bind to Ctrl+`. Dev mode (when
BRIDGE_URL is set, no bundled child) renders an explanatory hint.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

examples/todo/qml/Main.qml

@@ -200,8 +200,21 @@ ApplicationWindow {
                     }
                 }
             }
+
+            DevConsole {
+                id: devConsole
+                visible: false
+                Layout.fillWidth: true
+                Layout.preferredHeight: 220
             }
         }
+    }
+
+    // Ctrl+`  toggles the FrankenPHP child output console (Phase 5 §13).
+    Shortcut {
+        sequences: ["Ctrl+`", "Ctrl+~"]
+        onActivated: devConsole.visible = !devConsole.visible
+    }
 
     Connections {
         target: SingleInstance

framework/qml/CMakeLists.txt

@@ -38,6 +38,7 @@ qt_add_qml_module(php_qml_bridge
     QML_FILES
         qml/RestClient.qml
         qml/AppShell.qml
+        qml/DevConsole.qml
 )
 
 target_include_directories(php_qml_bridge PUBLIC src/)

framework/qml/qml/DevConsole.qml

@@ -0,0 +1,138 @@
+import QtQuick
+import QtQuick.Controls
+import QtQuick.Layouts
+import PhpQml.Bridge
+
+// Optional in-window log viewer for the bundled FrankenPHP child's
+// stdout+stderr. Captured passively in BackendConnection (see PLAN.md
+// §13 Phase 5 sub-commit 1) so opening the console is free — there is
+// no IPC cost, just rendering a ring buffer the host already keeps.
+//
+// Drop one into a Window/ApplicationWindow and toggle `visible`. The
+// skeleton's Main.qml binds Ctrl+` to flip visibility.
+//
+// Dev mode (BRIDGE_URL set): childLogTail() returns empty; the console
+// renders a hint that there's no bundled child to observe.
+Rectangle {
+    id: console_
+
+    color: "#0e1116"
+    border.color: "#2a3138"
+    border.width: 1
+    radius: 4
+
+    // The view is implicitly tied to a fixed-pitch font for log alignment.
+    readonly property int maxLines: 500
+
+    ListModel { id: lineModel }
+
+    function append(line) {
+        lineModel.append({ "text": line });
+        while (lineModel.count > maxLines) {
+            lineModel.remove(0);
+        }
+        if (autoScroll.checked) {
+            view.positionViewAtEnd();
+        }
+    }
+
+    function reseed() {
+        lineModel.clear();
+        const tail = BackendConnection.childLogTail();
+        for (let i = 0; i < tail.length; ++i) {
+            lineModel.append({ "text": tail[i] });
+        }
+        if (autoScroll.checked) {
+            view.positionViewAtEnd();
+        }
+    }
+
+    Component.onCompleted: reseed()
+
+    onVisibleChanged: {
+        // Re-seed whenever the user re-opens the console so they see the
+        // latest tail rather than a stale snapshot from the first open.
+        if (visible) reseed();
+    }
+
+    Connections {
+        target: BackendConnection
+        function onChildLogLine(line) { console_.append(line); }
+    }
+
+    ColumnLayout {
+        anchors.fill: parent
+        anchors.margins: 6
+        spacing: 4
+
+        RowLayout {
+            Layout.fillWidth: true
+            spacing: 8
+
+            Label {
+                text: BackendConnection.mode === BackendConnection.Bundled
+                      ? "FrankenPHP — child output"
+                      : "Dev mode — no bundled child to capture"
+                color: "#cbd5e1"
+                font.pixelSize: 12
+                font.bold: true
+                Layout.fillWidth: true
+                elide: Label.ElideRight
+            }
+            CheckBox {
+                id: autoScroll
+                text: "Auto-scroll"
+                checked: true
+                contentItem: Label {
+                    text: autoScroll.text
+                    color: "#cbd5e1"
+                    leftPadding: autoScroll.indicator.width + 4
+                    verticalAlignment: Text.AlignVCenter
+                }
+            }
+            Button {
+                text: "Clear"
+                onClicked: lineModel.clear()
+            }
+        }
+
+        Rectangle {
+            Layout.fillWidth: true
+            Layout.fillHeight: true
+            color: "#0b0d10"
+            border.color: "#1f242b"
+            border.width: 1
+
+            ListView {
+                id: view
+                anchors.fill: parent
+                anchors.margins: 4
+                model: lineModel
+                clip: true
+                cacheBuffer: 200
+
+                ScrollBar.vertical: ScrollBar { policy: ScrollBar.AsNeeded }
+
+                delegate: Label {
+                    width: view.width
+                    text: model.text
+                    color: "#d6dee7"
+                    font.family: "monospace"
+                    font.pixelSize: 11
+                    wrapMode: Text.NoWrap
+                    elide: Label.ElideRight
+                }
+            }
+
+            Label {
+                anchors.centerIn: parent
+                visible: lineModel.count === 0
+                text: BackendConnection.mode === BackendConnection.Bundled
+                      ? "(no output yet)"
+                      : "(dev mode — observe your terminal instead)"
+                color: "#5a6674"
+                font.pixelSize: 12
+            }
+        }
+    }
+}

framework/qml/src/BackendConnection.cpp

@@ -261,7 +261,11 @@ bool BackendConnection::spawnChild(QString* errorOut)
     env.insert(QStringLiteral("MERCURE_PUBLISHER_JWT_KEY"),  m_jwtSecret);
     env.insert(QStringLiteral("MERCURE_SUBSCRIBER_JWT_KEY"), m_jwtSecret);
     m_child->setProcessEnvironment(env);
-    m_child->setProcessChannelMode(QProcess::ForwardedChannels);
+    // Capture both streams into a single chronological buffer so the
+    // DevConsole sees stderr (FrankenPHP / Symfony logs) interleaved with
+    // stdout the same way a TTY would. The console keeps still emitting
+    // each line via qCInfo(lcBundled) so terminal users aren't blinded.
+    m_child->setProcessChannelMode(QProcess::MergedChannels);
 
     // Linux: kernel kills the child if the parent dies for any reason.
     m_child->setChildProcessModifier([] {
@@ -270,6 +274,8 @@ bool BackendConnection::spawnChild(QString* errorOut)
 
     connect(m_child, &QProcess::finished,
             this, &BackendConnection::onChildFinished);
+    connect(m_child, &QProcess::readyReadStandardOutput,
+            this, &BackendConnection::onChildOutputReady);
 
     qCInfo(lcBundled) << "spawning frankenphp on port" << m_port;
     m_child->start();
@@ -296,6 +302,38 @@ void BackendConnection::teardownChild()
     disconnect(m_child, nullptr, this, nullptr);
     m_child->deleteLater();
     m_child = nullptr;
+    m_childLogBuffer.clear();
+}
+
+void BackendConnection::onChildOutputReady()
+{
+    if (!m_child) return;
+    m_childLogBuffer += QString::fromUtf8(m_child->readAllStandardOutput());
+
+    int nl;
+    while ((nl = m_childLogBuffer.indexOf(QLatin1Char('\n'))) >= 0) {
+        QString line = m_childLogBuffer.left(nl);
+        m_childLogBuffer.remove(0, nl + 1);
+        if (line.endsWith(QLatin1Char('\r'))) {
+            line.chop(1);
+        }
+        qCInfo(lcBundled).noquote() << line;
+        m_childLog.enqueue(line);
+        while (m_childLog.size() > kChildLogMax) {
+            m_childLog.dequeue();
+        }
+        emit childLogLine(line);
+    }
+}
+
+QStringList BackendConnection::childLogTail() const
+{
+    QStringList out;
+    out.reserve(m_childLog.size());
+    for (const QString& l : m_childLog) {
+        out.append(l);
+    }
+    return out;
 }
 
 void BackendConnection::onChildFinished(int exitCode, QProcess::ExitStatus status)

framework/qml/src/BackendConnection.h

@@ -3,7 +3,9 @@
 #include <QElapsedTimer>
 #include <QObject>
 #include <QProcess>
+#include <QQueue>
 #include <QString>
+#include <QStringList>
 #include <QtQmlIntegration>
 
 class QNetworkAccessManager;
@@ -78,6 +80,11 @@ public:
     /// after this completes; emits `updateApplied` / `updateApplyFailed`.
     Q_INVOKABLE void applyUpdate();
 
+    /// Returns a snapshot of the captured child stdout/stderr ring buffer
+    /// (most recent kChildLogMax lines). Bundled mode only — empty in dev
+    /// mode. Used by `DevConsole.qml` to seed its view on first show.
+    Q_INVOKABLE QStringList childLogTail() const;
+
 signals:
     void urlChanged();
     void tokenChanged();
@@ -94,10 +101,16 @@ signals:
     void updateApplied();
     void updateApplyFailed(const QString& reason);
 
+    /// Emitted for each newline-terminated chunk read from the bundled
+    /// FrankenPHP child's merged stdout+stderr stream. DevConsole.qml
+    /// listens for these to populate its log view live.
+    void childLogLine(const QString& line);
+
 private slots:
     void probe();
     void onProbeFinished();
     void onChildFinished(int exitCode, QProcess::ExitStatus status);
+    void onChildOutputReady();
     void onUpdateCheckFinished(int exitCode, QProcess::ExitStatus status);
     void onUpdateApplyFinished(int exitCode, QProcess::ExitStatus status);
 
@@ -138,6 +151,10 @@ private:
     int m_supervisorRetries = 0;
     static constexpr int kMaxSupervisorRetries = 5;
 
+    QQueue<QString> m_childLog;
+    QString m_childLogBuffer;
+    static constexpr int kChildLogMax = 500;
+
     QProcess* m_updateCheck = nullptr;
     QProcess* m_updateApply = nullptr;
 

framework/skeleton/qml/Main.qml

@@ -124,6 +124,19 @@ ApplicationWindow {
                 }
             }
         }
+
+        DevConsole {
+            id: devConsole
+            visible: false
+            Layout.fillWidth: true
+            Layout.preferredHeight: 220
+        }
+    }
+
+    // Ctrl+`  toggles the FrankenPHP child output console (Phase 5 §13).
+    Shortcut {
+        sequences: ["Ctrl+`", "Ctrl+~"]
+        onActivated: devConsole.visible = !devConsole.visible
     }
 
     function _stateName(s) {