feat(acp): show subagent cards, fix layout

Subagent tool calls need identifiable instructions on the card
and in history so parent runs stay readable after reload. Cap
stored text so large omp task batches cannot bloat the session.

Long agent/user text must not drive minimum widths past the
transcript; that made QBoxLayout size to the minimum, squashing
rows and clipping the last lines under AlignRight.

Author: nullmastermind

src/AcpProtocol.cpp

@@ -580,6 +580,92 @@ QString subagentParentToolCallId(const QJsonObject &update)
     return parent;
 }
 
+namespace {
+
+constexpr int kMaxHistoryInstructionChars = 32000;
+
+bool isOmpTaskInput(const QJsonObject &rawInput)
+{
+    const QJsonValue tasks = rawInput.value(QLatin1String("tasks"));
+    if (!tasks.isArray()) return false;
+    const QJsonArray arr = tasks.toArray();
+    return !arr.isEmpty() && arr.first().toObject().value(QLatin1String("task")).isString();
+}
+
+} // namespace
+
+bool isSubagentToolInput(const QJsonObject &rawInput)
+{
+    if (rawInput.contains(QLatin1String("subagent_type")))
+        return true;
+    if (rawInput.contains(QLatin1String("description"))
+        && !rawInput.value(QLatin1String("prompt")).toString().isEmpty())
+        return true; // WebFetch's prompt comes with a url, not a description
+    return isOmpTaskInput(rawInput);
+}
+
+int subagentToolCount(const QJsonObject &rawInput)
+{
+    return isOmpTaskInput(rawInput)
+        ? static_cast<int>(rawInput.value(QLatin1String("tasks")).toArray().size())
+        : 1;
+}
+
+QString subagentInstructions(const QJsonObject &rawInput)
+{
+    if (!isOmpTaskInput(rawInput)) {
+        if (!isSubagentToolInput(rawInput)) return {};
+        return rawInput.value(QLatin1String("prompt")).toString().trimmed();
+    }
+    QString md = rawInput.value(QLatin1String("context")).toString().trimmed();
+    const QJsonArray tasks = rawInput.value(QLatin1String("tasks")).toArray();
+    for (const QJsonValue &v : tasks) {
+        const QJsonObject task = v.toObject();
+        const QString text = task.value(QLatin1String("task")).toString().trimmed();
+        const QString name = task.value(QLatin1String("name")).toString().trimmed();
+        if (text.isEmpty() && name.isEmpty()) continue;
+        if (!md.isEmpty()) md += QLatin1String("\n\n");
+        if (!name.isEmpty())
+            md += QLatin1String("**") + name + QLatin1String("**\n\n");
+        md += text;
+    }
+    return md;
+}
+
+QJsonObject subagentInputForHistory(const QJsonObject &rawInput)
+{
+    auto capped = [](QString text) {
+        if (text.size() > kMaxHistoryInstructionChars) text.truncate(kMaxHistoryInstructionChars);
+        return text;
+    };
+    QJsonObject out;
+    if (!isOmpTaskInput(rawInput)) {
+        const QString prompt = rawInput.value(QLatin1String("prompt")).toString();
+        if (!prompt.isEmpty()) out.insert(QStringLiteral("prompt"), capped(prompt));
+        return out;
+    }
+    for (const QLatin1String key : {QLatin1String("i"), QLatin1String("agent")}) {
+        const QString value = rawInput.value(key).toString();
+        if (!value.isEmpty()) out.insert(key, value.left(200));
+    }
+    // One budget across the context and every task.
+    int budget = kMaxHistoryInstructionChars;
+    const QString context = rawInput.value(QLatin1String("context")).toString().left(budget);
+    budget -= static_cast<int>(context.size());
+    if (!context.isEmpty()) out.insert(QStringLiteral("context"), context);
+    QJsonArray tasks;
+    const QJsonArray source = rawInput.value(QLatin1String("tasks")).toArray();
+    for (const QJsonValue &v : source) {
+        const QJsonObject task = v.toObject();
+        const QString text = task.value(QLatin1String("task")).toString().left(qMax(0, budget));
+        budget -= static_cast<int>(text.size());
+        tasks.append(QJsonObject{{QStringLiteral("name"), task.value(QLatin1String("name")).toString()},
+                                 {QStringLiteral("task"), text}});
+    }
+    out.insert(QStringLiteral("tasks"), tasks);
+    return out;
+}
+
 QString formatWaitDuration(qint64 ms)
 {
     if (ms < 0) {

src/AcpProtocol.h

@@ -358,6 +358,18 @@ bool toolCallUpdateIsBackgrounded(const QJsonObject &update);
 // when the id names the update's own tool call.
 QString subagentParentToolCallId(const QJsonObject &update);
 
+// A tool call that runs subagents, from its rawInput: Claude Code's Agent/Task
+// (`subagent_type`, or `description` + `prompt`) or omp's task
+// (`tasks: [{name, task}]`, optional `context`, `agent`, intent `i`).
+bool isSubagentToolInput(const QJsonObject &rawInput);
+// Number of subagents the call starts: omp's task count, else 1.
+int subagentToolCount(const QJsonObject &rawInput);
+// The instructions those subagents get, as markdown (omp: the shared context,
+// then each task under its bold name). Empty when the call carries none.
+QString subagentInstructions(const QJsonObject &rawInput);
+// The rawInput fields history keeps for such a call (instructions capped).
+QJsonObject subagentInputForHistory(const QJsonObject &rawInput);
+
 // Compact wait clock: "4.2s" under a minute, "2m 05s" under an hour, then "1h 02m".
 QString formatWaitDuration(qint64 ms);
 // Compact tool run time: "<1s", "40s", "1m5s", "1h1m5s".

src/AcpSessionModel.cpp

@@ -376,6 +376,13 @@ QJsonObject AcpSessionModel::toHistoryJson() const
             copyField(QLatin1String("information_request"));
             copyField(QLatin1String("skill"));
             copyField(QLatin1String("subagent_type"));
+            // A subagent call's instructions: its card shows them above the
+            // subagent's calls, and they mark the card as a subagent's.
+            if (AcpProtocol::isSubagentToolInput(tc.rawInput)) {
+                const QJsonObject kept = AcpProtocol::subagentInputForHistory(tc.rawInput);
+                for (auto it = kept.constBegin(); it != kept.constEnd(); ++it)
+                    slim.insert(it.key(), it.value());
+            }
             if (tc.rawInput.contains(QLatin1String("command"))) {
                 QString cmd = tc.rawInput.value(QLatin1String("command")).toString();
                 if (cmd.isEmpty() && tc.rawInput.value(QLatin1String("command")).isArray()) {

src/icons/bot.svg

@@ -51,6 +51,7 @@
         <file>icons/square-terminal.svg</file>
         <file>icons/play.svg</file>
         <file>icons/check.svg</file>
+        <file>icons/bot.svg</file>
         <file>icons/circle-x.svg</file>
         <file>icons/eraser.svg</file>
         <file>icons/chevron-up.svg</file>

src/resources.qrc

@@ -53,6 +53,8 @@
 
 #include <cmath>
 #include <cstdint>
+#include <functional>
+#include <utility>
 
 namespace {
 
@@ -76,6 +78,44 @@ constexpr int kThoughtBrowserPadLeft = 4;
 constexpr int kUserBubblePadH = 14;
 constexpr int kUserBubbleGap = 32; // space kept free to the left of a full-width user bubble
 constexpr int kThoughtItalicRightSlack = 4;
+
+// A word that cannot wrap (a path, a URL) must not set the bubble's minimum
+// width. A bubble whose minimum is wider than the transcript gets laid out by
+// QBoxLayout for its minimum width, not the width it has: the height comes out
+// short and the last lines are clipped. The word is clipped instead.
+void allowShrink(QWidget *w)
+{
+    w->setMinimumWidth(1);
+}
+
+// The transcript layout asks a bubble's layout (QWidgetItem::heightForWidth),
+// not the bubble, for its height at the full transcript width; AlignRight then
+// narrows the bubble to its hint. Answer for the width the bubble really gets,
+// or lines that wrap only at that width are clipped.
+class UserBubbleLayout : public QVBoxLayout
+{
+public:
+    UserBubbleLayout(QWidget *parent, std::function<int()> width)
+        : QVBoxLayout(parent)
+        , m_width(std::move(width))
+    {
+    }
+
+    int heightForWidth(int w) const override { return QVBoxLayout::heightForWidth(qMin(w, m_width())); }
+
+    // Runs on every text, font or visibility change of a child.
+    void invalidate() override
+    {
+        contentWidth = -1;
+        QVBoxLayout::invalidate();
+    }
+
+    // AcpMessageWidget::measureUserContent() (text shaping), -1 = stale.
+    mutable int contentWidth = -1;
+
+private:
+    std::function<int()> m_width;
+};
 // Final-report action row: square icon buttons, glyph per ui-dna toolbar chrome.
 constexpr int kResponseActionsH = 22;
 constexpr int kResponseActionIcon = 14;
@@ -135,7 +175,11 @@ AcpMessageWidget::AcpMessageWidget(QString role, QWidget *parent)
                   QString::fromLatin1(kFrameStyleThought) +
                   QString::fromLatin1(kFrameStyleSystem));
 
-    m_layout = new QVBoxLayout(this);
+    if (m_role == QLatin1String("user")) {
+        m_layout = new UserBubbleLayout(this, [this]() { return userBubbleWidth(); });
+    } else {
+        m_layout = new QVBoxLayout(this);
+    }
     if (m_role == QLatin1String("thought")) {
         m_layout->setContentsMargins(4, 4, 4, 4);
     } else if (m_role == QLatin1String("user")) {
@@ -300,6 +344,7 @@ void AcpMessageWidget::setContent(const QVector<AcpProtocol::AcpContentBlock> &c
                 if (!pendingTextLabel) {
                     pendingTextLabel = new QLabel(this);
                     pendingTextLabel->setWordWrap(true);
+                    allowShrink(pendingTextLabel);
                     pendingTextLabel->setTextInteractionFlags(Qt::TextSelectableByMouse);
                     // Stamp the chat font now: this QLabel is created after the
                     // view's initial setChatFont() pass, and being inside a
@@ -360,6 +405,7 @@ void AcpMessageWidget::setCollapsedSummary(const QString &summary, const QString
         m_summaryHeader->setCheckable(true);
         m_summaryHeader->setAutoRaise(true);
         m_summaryHeader->setToolButtonStyle(Qt::ToolButtonTextOnly);
+        allowShrink(m_summaryHeader);
         m_summaryHeader->setStyleSheet(QStringLiteral(
             "QToolButton { border: none; padding: 0; margin: 0; text-align: left; }"));
         m_summaryHeader->setCursor(Qt::PointingHandCursor);
@@ -369,6 +415,7 @@ void AcpMessageWidget::setCollapsedSummary(const QString &summary, const QString
         m_summaryOverview = new QLabel(this);
         m_summaryOverview->setTextFormat(Qt::PlainText);
         m_summaryOverview->setWordWrap(true);
+        allowShrink(m_summaryOverview);
         m_summaryOverview->setTextInteractionFlags(Qt::TextSelectableByMouse);
         if (m_chatFontSet)
             m_summaryOverview->setFont(m_chatFont);
@@ -463,8 +510,28 @@ QSize AcpMessageWidget::sizeHint() const
     if (m_role != QLatin1String("user") || !m_layout)
         return QFrame::sizeHint();
 
+    const int w = userBubbleWidth();
+    const int h = m_layout->hasHeightForWidth() ? m_layout->totalHeightForWidth(w)
+                                                : QFrame::sizeHint().height();
+    return QSize(w, h);
+}
+
+int AcpMessageWidget::userBubbleWidth() const
+{
     int marginL = 0, marginT = 0, marginR = 0, marginB = 0;
     m_layout->getContentsMargins(&marginL, &marginT, &marginR, &marginB);
+    const auto *layout = static_cast<const UserBubbleLayout *>(m_layout);
+    if (layout->contentWidth < 0)
+        layout->contentWidth = measureUserContent();
+    // +2 border, +2 so a line that exactly fits is not wrapped by rounding.
+    int w = layout->contentWidth + marginL + marginR + 4;
+    if (const QWidget *host = parentWidget())
+        w = qMin(w, qMax(host->width() - kUserBubbleGap, 120));
+    return w;
+}
+
+int AcpMessageWidget::measureUserContent() const
+{
     int contentW = 0;
     if (m_summaryHeader)
         contentW = m_summaryHeader->sizeHint().width();
@@ -487,13 +554,7 @@ QSize AcpMessageWidget::sizeHint() const
         if (!ui.original.isNull() && !ui.label->isHidden())
             contentW = qMax(contentW, ui.original.width());
     }
-    // +2 border, +2 so a line that exactly fits is not wrapped by rounding.
-    int w = contentW + marginL + marginR + 4;
-    if (const QWidget *host = parentWidget())
-        w = qMin(w, qMax(host->width() - kUserBubbleGap, 120));
-    const int h = m_layout->hasHeightForWidth() ? m_layout->totalHeightForWidth(w)
-                                                : QFrame::sizeHint().height();
-    return QSize(w, h);
+    return contentW;
 }
 
 void AcpMessageWidget::refitBrowserHeight()

src/widgets/AcpMessageWidget.cpp

@@ -118,6 +118,12 @@ class AcpMessageWidget : public QFrame
     bool eventFilter(QObject *watched, QEvent *event) override;
 
 private:
+    // The width sizeHint() reports for a user bubble: its widest line, capped
+    // to the transcript.
+    int userBubbleWidth() const;
+    // Widest unwrapped line / image of a user bubble (text shaping: cached by
+    // its layout until a child changes).
+    int measureUserContent() const;
     void rerender();
     void refitBrowserHeight();
     void scheduleRefit();
@@ -148,7 +154,7 @@ class AcpMessageWidget : public QFrame
     QLabel *m_summaryOverview = nullptr;    // one line per answer while collapsed
     QString m_summary;
     QLabel *m_goalBadge = nullptr;         // Goal badge on result rows
-    QVBoxLayout *m_layout = nullptr;
+    QVBoxLayout *m_layout = nullptr; // user role: UserBubbleLayout
 
     // Final-report action row (assistant role), built on first enable.
     QWidget *m_responseActions = nullptr;