kde/gui: Acme-style mouse actions and one-handed workflow

Add Plan 9/Acme-inspired mouse interaction:
- B2 (middle-click): Execute selected text as prompt
- B3 (right-click): Plumb selection via plan9port, fallback to context menu

Plumber integration (plumber.h/cpp):
- Wraps plan9port's plumb command for context-aware actions
- Auto-detects plumb binary in common plan9port locations
- Graceful fallback when plumber not available

Block tag line (ChatBlockDelegate):
- Hover-visible action buttons: Copy, Retry, Continue, Edit
- Per-block-type actions (Retry for assistant/error, Edit for user)

Action toolbar (ChatPane):
- Stop, Compact, Copy Last, Templates dropdown
- Mouse-first workflow without keyboard shortcuts

Input area improvements:
- Larger touch targets (48px send button, 32px toggle)
- Clear and Paste buttons
- B2/B3 mouse actions in prompt input
- Placeholder text explains mouse actions

Context menus now include:
- Execute Selection (B2)
- Plumb Selection (B3)
- Standard Cut/Copy/Paste/Select All

kde/CMakeLists.txt

@@ -152,6 +152,7 @@ if(OLLIE_KF5)
         gui/chatblockmodel.cpp
         gui/thememanager.cpp
         gui/clipboardhelper.cpp
+        gui/plumber.cpp
         ${GUI_KF5_QRC}
     )
     add_dependencies(ollie-gui lib9p_build)
@@ -244,6 +245,7 @@ else()
         gui/chatblockmodel.cpp
         gui/thememanager.cpp
         gui/clipboardhelper.cpp
+        gui/plumber.cpp
     )
     add_dependencies(ollie-gui lib9p_build)
     target_include_directories(ollie-gui PRIVATE

kde/gui/ChatBlockDelegate.qml

@@ -1,4 +1,8 @@
 // ChatBlockDelegate.qml — Delegate for rendering chat blocks in the ListView
+// Acme-style mouse actions:
+//   B1 = select (default)
+//   B2 (middle-click) = execute selection as prompt
+//   B3 (right-click) = plumb to plan9port / context menu
 import QtQuick 2.15
 import QtQuick.Controls 2.15
 import QtQuick.Layouts 1.15
@@ -28,6 +32,9 @@ Column {
         }
     }
 
+    // Show action buttons on hover
+    property bool hovered: headerArea.containsMouse || contentArea.containsMouse
+
     // Header color based on block type and theme
     function headerColor() {
         var bg = theme.baseColor
@@ -76,15 +83,17 @@ Column {
         }
     }
 
-    // Clickable header
+    // Clickable header with action buttons
     Rectangle {
         width: root.width
-        height: 22
+        height: 28
         radius: 3
         color: root.headerColor()
 
         MouseArea {
+            id: headerArea
             anchors.fill: parent
+            hoverEnabled: true
             cursorShape: Qt.PointingHandCursor
             onClicked: root.blockExpanded = !root.blockExpanded
         }
@@ -92,6 +101,7 @@ Column {
         RowLayout {
             anchors.fill: parent
             anchors.leftMargin: 6
+            anchors.rightMargin: 6
             spacing: 4
 
             Label {
@@ -108,15 +118,86 @@ Column {
                 color: theme.textColor
                 opacity: 0.9
             }
+
+            // Action buttons (visible on hover) — Acme-style tag line
+            Row {
+                spacing: 2
+                visible: root.hovered
+                opacity: 0.8
+
+                // Copy block content
+                ToolButton {
+                    text: "📋"
+                    font.pixelSize: 12
+                    implicitWidth: 24
+                    implicitHeight: 22
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Copy"
+                    onClicked: {
+                        var content = getBlockPlainText()
+                        if (content) clipboard.copyText(content)
+                    }
+                }
+
+                // Retry (assistant blocks only)
+                ToolButton {
+                    text: "🔄"
+                    font.pixelSize: 12
+                    implicitWidth: 24
+                    implicitHeight: 22
+                    visible: blockType === "assistant" || blockType === "error"
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Retry"
+                    onClicked: ollie.submit("retry")
+                }
+
+                // Continue (assistant blocks only)
+                ToolButton {
+                    text: "➡️"
+                    font.pixelSize: 12
+                    implicitWidth: 24
+                    implicitHeight: 22
+                    visible: blockType === "assistant"
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Continue"
+                    onClicked: ollie.submit("continue")
+                }
+
+                // Edit & Resend (user blocks only)
+                ToolButton {
+                    text: "✏️"
+                    font.pixelSize: 12
+                    implicitWidth: 24
+                    implicitHeight: 22
+                    visible: blockType === "user"
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Edit & Resend"
+                    onClicked: {
+                        var content = getBlockPlainText()
+                        // Find the prompt input and set its text
+                        // This requires the parent ChatPane to expose the input
+                        chatPane.setPromptText(content)
+                    }
+                }
+            }
         }
     }
 
     // Block content rendered as segments
     Column {
+        id: contentColumn
         width: root.width
         visible: root.blockExpanded
         spacing: 4
 
+        MouseArea {
+            id: contentArea
+            anchors.fill: parent
+            hoverEnabled: true
+            propagateComposedEvents: true
+            acceptedButtons: Qt.NoButton
+        }
+
         // Fast path: single TextEdit for the concatenated HTML.
         // Diagrams are handled separately via the segments list.
         TextEdit {
@@ -134,15 +215,36 @@ Column {
             selectionColor: theme.highlightColor
             selectedTextColor: theme.highlightedTextColor
 
+            // Acme-style mouse handling: B2=execute, B3=plumb/menu
             MouseArea {
                 anchors.fill: parent
-                acceptedButtons: Qt.RightButton
+                acceptedButtons: Qt.MiddleButton | Qt.RightButton
                 cursorShape: Qt.IBeamCursor
-                onClicked: {
+                propagateComposedEvents: true
-                    if (!mainTextEdit._menu) {
+
-                        mainTextEdit._menu = contextMenuComponent.createObject(mainTextEdit)
+                onClicked: function(mouse) {
+                    if (mouse.button === Qt.MiddleButton) {
+                        // B2: Execute selection as prompt
+                        var sel = mainTextEdit.selectedText
+                        if (sel && sel.trim() !== "") {
+                            executeText(sel)
+                        }
+                        mouse.accepted = true
+                    } else if (mouse.button === Qt.RightButton) {
+                        // B3: Plumb selection, or show context menu
+                        var sel = mainTextEdit.selectedText
+                        if (sel && sel.trim() !== "" && plumber.available()) {
+                            plumber.plumb(sel.trim())
+                            mouse.accepted = true
+                        } else {
+                            // Fall back to context menu
+                            if (!mainTextEdit._menu) {
+                                mainTextEdit._menu = contextMenuComponent.createObject(mainTextEdit)
+                            }
+                            mainTextEdit._menu.popup()
+                            mouse.accepted = true
+                        }
                     }
-                    mainTextEdit._menu.popup()
                 }
             }
             property var _menu: null
@@ -170,6 +272,51 @@ Column {
         return false
     }
 
+    // Get plain text content of this block
+    function getBlockPlainText() {
+        // Use the mainTextEdit's text property stripped of HTML
+        if (mainTextEdit.visible) {
+            return mainTextEdit.getText(0, mainTextEdit.length)
+        }
+        // For diagram blocks, concatenate segment text
+        var text = ""
+        if (root.blockSegments) {
+            for (var i = 0; i < root.blockSegments.length; i++) {
+                var seg = root.blockSegments[i]
+                if (seg && seg.source) text += seg.source + "\n"
+            }
+        }
+        return text.trim()
+    }
+
+    // Execute text: send as prompt or wrap if it looks like code
+    function executeText(text) {
+        if (!text || text.trim() === "") return
+        var trimmed = text.trim()
+
+        // If multi-line or looks like code, wrap in "run this"
+        if (trimmed.indexOf('\n') >= 0 || looksLikeCommand(trimmed)) {
+            ollie.submit("Run this:\n```\n" + trimmed + "\n```")
+        } else {
+            ollie.submit(trimmed)
+        }
+    }
+
+    // Detect if text looks like an executable command
+    function looksLikeCommand(text) {
+        var cmdPrefixes = [
+            "ls", "cd", "cat", "grep", "find", "make", "go ", "npm", "yarn",
+            "git ", "docker", "kubectl", "curl", "wget", "ssh", "scp",
+            "python", "node", "ruby", "cargo", "rustc", "gcc", "clang",
+            "./", "sudo"
+        ]
+        var lower = text.toLowerCase().trim()
+        for (var i = 0; i < cmdPrefixes.length; i++) {
+            if (lower.startsWith(cmdPrefixes[i])) return true
+        }
+        return false
+    }
+
     // Text segment component
     Component {
         id: textComponent
@@ -188,17 +335,33 @@ Column {
             selectionColor: theme.highlightColor
             selectedTextColor: theme.highlightedTextColor
 
-            // Left-click: disable ListView flick while selecting text
+            // Acme-style mouse handling
-            // Right-click: lazy context menu
             MouseArea {
                 anchors.fill: parent
-                acceptedButtons: Qt.RightButton
+                acceptedButtons: Qt.MiddleButton | Qt.RightButton
                 cursorShape: Qt.IBeamCursor
-                onClicked: {
+                propagateComposedEvents: true
-                    if (!textEdit._menu) {
+
-                        textEdit._menu = contextMenuComponent.createObject(textEdit)
+                onClicked: function(mouse) {
+                    if (mouse.button === Qt.MiddleButton) {
+                        var sel = textEdit.selectedText
+                        if (sel && sel.trim() !== "") {
+                            executeText(sel)
+                        }
+                        mouse.accepted = true
+                    } else if (mouse.button === Qt.RightButton) {
+                        var sel = textEdit.selectedText
+                        if (sel && sel.trim() !== "" && plumber.available()) {
+                            plumber.plumb(sel.trim())
+                            mouse.accepted = true
+                        } else {
+                            if (!textEdit._menu) {
+                                textEdit._menu = contextMenuComponent.createObject(textEdit)
+                            }
+                            textEdit._menu.popup()
+                            mouse.accepted = true
+                        }
                     }
-                    textEdit._menu.popup()
                 }
             }
 
@@ -216,6 +379,18 @@ Column {
         Menu {
             id: ctxMenu
             property TextEdit target: parent
+
+            MenuItem {
+                text: "Execute (B2)"
+                enabled: ctxMenu.target ? ctxMenu.target.selectedText.length > 0 : false
+                onTriggered: if (ctxMenu.target) executeText(ctxMenu.target.selectedText)
+            }
+            MenuItem {
+                text: "Plumb (B3)"
+                enabled: ctxMenu.target ? ctxMenu.target.selectedText.length > 0 && plumber.available() : false
+                onTriggered: if (ctxMenu.target) plumber.plumb(ctxMenu.target.selectedText.trim())
+            }
+            MenuSeparator {}
             MenuItem {
                 text: "Copy"
                 enabled: ctxMenu.target ? ctxMenu.target.selectedText.length > 0 : false
@@ -312,13 +487,26 @@ Column {
 
                     MouseArea {
                         anchors.fill: parent
-                        acceptedButtons: Qt.RightButton
+                        acceptedButtons: Qt.MiddleButton | Qt.RightButton
                         cursorShape: Qt.IBeamCursor
-                        onClicked: {
+                        propagateComposedEvents: true
-                            if (!sourceEdit._menu) {
+                        onClicked: function(mouse) {
-                                sourceEdit._menu = contextMenuComponent.createObject(sourceEdit)
+                            if (mouse.button === Qt.MiddleButton) {
+                                var sel = sourceEdit.selectedText
+                                if (sel && sel.trim() !== "") executeText(sel)
+                                mouse.accepted = true
+                            } else if (mouse.button === Qt.RightButton) {
+                                var sel = sourceEdit.selectedText
+                                if (sel && sel.trim() !== "" && plumber.available()) {
+                                    plumber.plumb(sel.trim())
+                                } else {
+                                    if (!sourceEdit._menu) {
+                                        sourceEdit._menu = contextMenuComponent.createObject(sourceEdit)
+                                    }
+                                    sourceEdit._menu.popup()
+                                }
+                                mouse.accepted = true
                             }
-                            sourceEdit._menu.popup()
                         }
                     }
                     property Menu _menu: null

kde/gui/ChatPane.qml

@@ -10,6 +10,12 @@ Item {
     // Do not opt the chat pane into focus navigation.
     activeFocusOnTab: false
 
+    // Expose method to set prompt text (for Edit & Resend)
+    function setPromptText(text) {
+        promptInput.text = text
+        promptInput.forceActiveFocus()
+    }
+
     function scrollToBottom() {
         chatView.positionViewAtEnd()
     }
@@ -44,12 +50,12 @@ Item {
                 Layout.margins: 6
                 spacing: 8
 
-                // Sidebar toggle button
+                // Sidebar toggle button (larger touch target)
                 ToolButton {
                     text: chatPane.sidebarVisible ? "◀" : "▶"
-                    font.pixelSize: 12
+                    font.pixelSize: 14
-                    implicitWidth: 24
+                    implicitWidth: 32
-                    implicitHeight: 24
+                    implicitHeight: 32
                     onClicked: chatPane.toggleSidebar()
                     ToolTip.text: chatPane.sidebarVisible ? "Hide sidebar (Ctrl+B)" : "Show sidebar (Ctrl+B)"
                     ToolTip.visible: hovered
@@ -144,6 +150,8 @@ Item {
 
                     delegate: ChatBlockDelegate {
                         width: chatView.width - 8
+                        // Pass reference to chatPane for Edit & Resend
+                        property var chatPane: chatPane
                     }
                 }
 
@@ -201,7 +209,80 @@ Item {
 
             Rectangle { Layout.fillWidth: true; height: 1; color: theme.midColor }
 
-            // Input
+            // Action toolbar — quick actions without keyboard
+            RowLayout {
+                id: actionToolbar
+                Layout.fillWidth: true
+                Layout.margins: 4
+                spacing: 4
+                visible: ollie.daemonConnected && ollie.activeAgentId !== ""
+
+                ToolButton {
+                    text: "⏹ Stop"
+                    font.pixelSize: theme.fontSize > 0 ? theme.fontSize * 0.9 : 11
+                    implicitHeight: 28
+                    enabled: ollie.activeState !== "idle"
+                    onClicked: ollie.interrupt()
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Stop the agent (Escape)"
+                }
+
+                ToolButton {
+                    text: "📦 Compact"
+                    font.pixelSize: theme.fontSize > 0 ? theme.fontSize * 0.9 : 11
+                    implicitHeight: 28
+                    onClicked: ollie.submit("compact")
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Compact context window"
+                }
+
+                ToolButton {
+                    text: "📋 Copy Last"
+                    font.pixelSize: theme.fontSize > 0 ? theme.fontSize * 0.9 : 11
+                    implicitHeight: 28
+                    enabled: chatModel.count > 0
+                    onClicked: {
+                        // Find last assistant block and copy its content
+                        for (var i = chatModel.count - 1; i >= 0; i--) {
+                            var block = chatModel.get(i)
+                            if (block && block.blockType === "assistant") {
+                                // The renderedHtml is HTML, but we want plain text
+                                // For now, copy the HTML - TODO: strip tags
+                                clipboard.copyText(block.blockRenderedHtml.replace(/<[^>]*>/g, ''))
+                                break
+                            }
+                        }
+                    }
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Copy last assistant response"
+                }
+
+                // Templates dropdown
+                ToolButton {
+                    id: templateButton
+                    text: "📝 Templates ▾"
+                    font.pixelSize: theme.fontSize > 0 ? theme.fontSize * 0.9 : 11
+                    implicitHeight: 28
+                    onClicked: templateMenu.popup()
+
+                    Menu {
+                        id: templateMenu
+                        MenuItem { text: "Explain this"; onTriggered: promptInput.text = "Explain this:\n" }
+                        MenuItem { text: "Fix the bug"; onTriggered: promptInput.text = "Fix the bug in " }
+                        MenuItem { text: "Write tests"; onTriggered: promptInput.text = "Write tests for " }
+                        MenuItem { text: "Summarize"; onTriggered: promptInput.text = "Summarize " }
+                        MenuItem { text: "Refactor"; onTriggered: promptInput.text = "Refactor " }
+                        MenuItem { text: "Add comments"; onTriggered: promptInput.text = "Add comments to " }
+                        MenuSeparator {}
+                        MenuItem { text: "Continue"; onTriggered: ollie.submit("continue") }
+                        MenuItem { text: "Retry"; onTriggered: ollie.submit("retry") }
+                    }
+                }
+
+                Item { Layout.fillWidth: true } // Spacer
+            }
+
+            // Input area
             RowLayout {
                 id: inputRow
                 Layout.fillWidth: true
@@ -215,6 +296,19 @@ Item {
                     }
                 }
 
+                // Clear button
+                ToolButton {
+                    text: "✕"
+                    font.pixelSize: 12
+                    implicitWidth: 28
+                    implicitHeight: 28
+                    Layout.alignment: Qt.AlignBottom
+                    visible: promptInput.text.length > 0
+                    onClicked: promptInput.text = ""
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Clear input"
+                }
+
                 // TextArea in ScrollView for overflow, with context menu overlay
                 Item {
                     Layout.fillWidth: true
@@ -235,7 +329,7 @@ Item {
                                 if (!ollie.activeSessionId) return "No session"
                                 if (!ollie.activeAgentId) return "No agent"
                                 if (ollie.isSessionPaused(ollie.activeSessionId)) return "Session paused"
-                                return "Message..."
+                                return "Message... (B2=execute selection, B3=plumb)"
                             }
                             enabled: ollie.daemonConnected && ollie.activeSessionId !== "" && ollie.activeAgentId !== "" && !ollie.isSessionPaused(ollie.activeSessionId)
                             wrapMode: TextEdit.Wrap
@@ -259,6 +353,18 @@ Item {
                                 }
                             }
 
+                            // Acme-style mouse handling in input
+                            TapHandler {
+                                acceptedButtons: Qt.MiddleButton
+                                onTapped: {
+                                    // B2: Execute selection as prompt immediately
+                                    var sel = promptInput.selectedText
+                                    if (sel && sel.trim() !== "") {
+                                        ollie.submit(sel.trim())
+                                    }
+                                }
+                            }
+
                             TapHandler {
                                 acceptedButtons: Qt.RightButton
                                 onTapped: promptContextMenu.popup()
@@ -268,6 +374,23 @@ Item {
 
                     Menu {
                         id: promptContextMenu
+                        MenuItem {
+                            text: "Execute Selection (B2)"
+                            enabled: promptInput.selectedText.length > 0
+                            onTriggered: {
+                                var sel = promptInput.selectedText
+                                if (sel && sel.trim() !== "") ollie.submit(sel.trim())
+                            }
+                        }
+                        MenuItem {
+                            text: "Plumb Selection (B3)"
+                            enabled: promptInput.selectedText.length > 0 && plumber.available()
+                            onTriggered: {
+                                var sel = promptInput.selectedText
+                                if (sel && sel.trim() !== "") plumber.plumb(sel.trim())
+                            }
+                        }
+                        MenuSeparator {}
                         MenuItem {
                             text: "Cut"
                             enabled: promptInput.selectedText.length > 0
@@ -291,11 +414,26 @@ Item {
                     }
                 }
 
+                // Paste button (mouse-first workflow)
+                ToolButton {
+                    text: "📋"
+                    font.pixelSize: 14
+                    implicitWidth: 36
+                    implicitHeight: 36
+                    Layout.alignment: Qt.AlignBottom
+                    enabled: promptInput.enabled
+                    onClicked: promptInput.paste()
+                    ToolTip.visible: hovered
+                    ToolTip.text: "Paste from clipboard"
+                }
+
+                // Send button (larger touch target)
                 Button {
                     text: "▶"
+                    font.pixelSize: 16
                     Layout.alignment: Qt.AlignBottom
-                    Layout.preferredWidth: 36
+                    Layout.preferredWidth: 48
-                    Layout.preferredHeight: 36
+                    Layout.preferredHeight: 48
                     focusPolicy: Qt.NoFocus
                     enabled: promptInput.enabled && promptInput.text.trim() !== ""
                     onClicked: inputRow.doSubmit()

kde/gui/main.cpp

@@ -16,6 +16,7 @@
 #include "chatblockmodel.h"
 #include "thememanager.h"
 #include "clipboardhelper.h"
+#include "plumber.h"
 
 int main(int argc, char *argv[])
 {
@@ -48,6 +49,7 @@ int main(int argc, char *argv[])
     auto *chatModel = new ChatBlockModel(&app);
     auto *theme = new ThemeManager(&app);
     auto *clipboard = new ClipboardHelper(&app);
+    auto *plumber = new Plumber(&app);
 
     QObject::connect(ollie, &Ollie9pClient::chatReceived,
                      chatModel, &ChatBlockModel::appendData);
@@ -58,6 +60,7 @@ int main(int argc, char *argv[])
     engine.rootContext()->setContextProperty("chatModel", chatModel);
     engine.rootContext()->setContextProperty("theme", theme);
     engine.rootContext()->setContextProperty("clipboard", clipboard);
+    engine.rootContext()->setContextProperty("plumber", plumber);
 
 const QUrl url(QStringLiteral("qrc:/main.qml"));
 

kde/gui/plumber.cpp

@@ -0,0 +1,94 @@
+#include "plumber.h"
+#include <QStandardPaths>
+#include <QFileInfo>
+#include <QDir>
+#include <QDebug>
+
+Plumber::Plumber(QObject *parent)
+    : QObject(parent)
+{
+    // Find plumb binary - check common plan9port locations
+    QStringList searchPaths = {
+        "/usr/local/plan9/bin/plumb",
+        "/usr/lib/plan9/bin/plumb",
+        QDir::homePath() + "/.local/plan9/bin/plumb",
+        QDir::homePath() + "/plan9port/bin/plumb"
+    };
+
+    // Also check PLAN9 environment variable
+    QString plan9 = qEnvironmentVariable("PLAN9");
+    if (!plan9.isEmpty()) {
+        searchPaths.prepend(plan9 + "/bin/plumb");
+    }
+
+    for (const QString &path : searchPaths) {
+        if (QFileInfo::exists(path)) {
+            m_plumbPath = path;
+            qDebug() << "Plumber: found plumb at" << m_plumbPath;
+            break;
+        }
+    }
+
+    if (m_plumbPath.isEmpty()) {
+        qDebug() << "Plumber: plumb binary not found, B3-plumb disabled";
+    }
+}
+
+bool Plumber::available() const
+{
+    return !m_plumbPath.isEmpty();
+}
+
+void Plumber::plumb(const QString &text)
+{
+    if (text.isEmpty()) return;
+
+    if (!available()) {
+        emit plumbError("plumb binary not found");
+        return;
+    }
+
+    QProcess *proc = new QProcess(this);
+    connect(proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
+            this, [this, proc](int exitCode, QProcess::ExitStatus status) {
+        if (exitCode != 0 || status != QProcess::NormalExit) {
+            QString err = proc->readAllStandardError();
+            if (!err.isEmpty()) {
+                emit plumbError(err);
+            }
+        }
+        proc->deleteLater();
+    });
+
+    // plumb reads from stdin
+    proc->start(m_plumbPath, QStringList());
+    proc->write(text.toUtf8());
+    proc->closeWriteChannel();
+}
+
+void Plumber::plumbTo(const QString &text, const QString &dst)
+{
+    if (text.isEmpty()) return;
+
+    if (!available()) {
+        emit plumbError("plumb binary not found");
+        return;
+    }
+
+    QProcess *proc = new QProcess(this);
+    connect(proc, QOverload<int, QProcess::ExitStatus>::of(&QProcess::finished),
+            this, [this, proc](int exitCode, QProcess::ExitStatus status) {
+        if (exitCode != 0 || status != QProcess::NormalExit) {
+            QString err = proc->readAllStandardError();
+            if (!err.isEmpty()) {
+                emit plumbError(err);
+            }
+        }
+        proc->deleteLater();
+    });
+
+    // plumb -d destination reads from stdin
+    proc->start(m_plumbPath, QStringList() << "-d" << dst);
+    proc->write(text.toUtf8());
+    proc->closeWriteChannel();
+}

kde/gui/plumber.h

@@ -0,0 +1,39 @@
+#ifndef PLUMBER_H
+#define PLUMBER_H
+
+#include <QObject>
+#include <QProcess>
+#if QT_VERSION_MAJOR >= 6
+#include <QQmlEngine>
+#endif
+
+// Plumber wraps plan9port's plumb command for context-aware actions.
+// B3-click on text → plumber routes to appropriate handler (editor, browser, etc.)
+class Plumber : public QObject
+{
+    Q_OBJECT
+#if QT_VERSION_MAJOR >= 6
+    QML_ELEMENT
+    QML_SINGLETON
+#endif
+
+public:
+    explicit Plumber(QObject *parent = nullptr);
+
+    // Plumb text to the plan9port plumber daemon
+    Q_INVOKABLE void plumb(const QString &text);
+
+    // Plumb with explicit source/destination
+    Q_INVOKABLE void plumbTo(const QString &text, const QString &dst);
+
+    // Check if plumber is available
+    Q_INVOKABLE bool available() const;
+
+signals:
+    void plumbError(const QString &error);
+
+private:
+    QString m_plumbPath;
+};
+
+#endif // PLUMBER_H