shell: Speech service + sidebar Speak button (Read Aloud seam)

Speech.qml singleton: speak(text) reads the who->voice mapping live
from souveraine /v1/config (VoiceConfig tts_url + voice_id), POSTs
VibeVoice /audio/speech ({input, voice, model} -> mp3, same contract
as core/voice/client.rs) and plays via mpv/ffplay. The shell picks no
voice of its own. speech.tts.enable is the kill switch (button hidden
when off); speech.tts.endpoint overrides the mapped URL. Sidebar gains
a volume_up/stop toggle beside send that reads the last visible
assistant reply, skipping lock-redacted content.

surfaces/quickshell/deploy.sh

@@ -40,6 +40,7 @@ services/SessionEvents.qml   souveraine/services/SessionEvents.qml
 services/SessiondBridge.qml  souveraine/services/SessiondBridge.qml
 services/StepUpAuth.qml      souveraine/services/StepUpAuth.qml
 services/SessionAudit.qml    souveraine/services/SessionAudit.qml
+services/Speech.qml          souveraine/services/Speech.qml
 services/NotifyEvents.qml    souveraine/services/NotifyEvents.qml
 services/CrashReporter.qml   souveraine/services/CrashReporter.qml
 modules/ii/sidebarLeft/SidebarLeft.qml    souveraine/modules/ii/sidebarLeft/SidebarLeft.qml

surfaces/quickshell/modules/ii/sidebarLeft/AiChat.qml

@@ -211,6 +211,20 @@ Inline w/ backslash and round brackets \\(e^{i\\pi} + 1 = 0\\)
         },
     ]
 
+    // Latest visible assistant reply — what the Speak button reads aloud.
+    // Skips lock-redacted content (LockContentPolicy swaps it for a marker).
+    function lastAssistantText() {
+        for (let i = Ai.messageIDs.length - 1; i >= 0; i--) {
+            const m = Ai.messageByID[Ai.messageIDs[i]];
+            if (m && m.role === "assistant" && (m.visibleToUser ?? true)
+                && m.content && m.content.length > 0
+                && !m.content.startsWith("[content hidden")) {
+                return m.content;
+            }
+        }
+        return "";
+    }
+
     function handleInput(inputText) {
         if (inputText.startsWith(root.commandPrefix)) {
             // Handle special commands
@@ -708,6 +722,34 @@ Inline w/ backslash and round brackets \\(e^{i\\pi} + 1 = 0\\)
                         }
                     }
                 }
+                RippleButton { // Speak button — read the last reply aloud
+                    id: speakButton
+                    visible: Speech.enabled
+                    Layout.alignment: Qt.AlignBottom
+                    Layout.rightMargin: 3
+                    implicitWidth: 40
+                    implicitHeight: 40
+                    buttonRadius: Appearance.rounding.small
+                    enabled: Speech.speaking || root.lastAssistantText().length > 0
+                    toggled: Speech.speaking
+
+                    MouseArea {
+                        anchors.fill: parent
+                        cursorShape: speakButton.enabled ? Qt.PointingHandCursor : Qt.ArrowCursor
+                        onClicked: {
+                            if (Speech.speaking) Speech.stop();
+                            else Speech.speak(root.lastAssistantText());
+                        }
+                    }
+
+                    contentItem: MaterialSymbol {
+                        anchors.centerIn: parent
+                        horizontalAlignment: Text.AlignHCenter
+                        iconSize: 22
+                        color: Speech.speaking ? Appearance.m3colors.m3onPrimary : (speakButton.enabled ? Appearance.colors.colOnLayer2 : Appearance.colors.colOnLayer2Disabled)
+                        text: Speech.speaking ? "stop_circle" : "volume_up"
+                    }
+                }
                 RippleButton { // Send button
                     id: sendButton
                     Layout.alignment: Qt.AlignBottom

surfaces/quickshell/services/Speech.qml

@@ -0,0 +1,119 @@
+pragma Singleton
+pragma ComponentBehavior: Bound
+
+import qs.modules.common
+import Quickshell
+import Quickshell.Io
+import QtQuick
+
+/**
+ * Speech — TTS egress for the shell (the Read Aloud seam, TASK-18).
+ *
+ * Souveraine owns the who→voice mapping: VoiceConfig in the consciousness
+ * config carries tts_url and voice_id, served live at /v1/config. This
+ * service reads that mapping on every speak() and posts the text to
+ * VibeVoice's /audio/speech (JSON {input, voice, model}, mp3 back — the
+ * same contract core/voice/client.rs speaks), then plays the result. The
+ * shell picks no voice of its own; souveraine decides how she sounds.
+ *
+ * Config.options.speech.tts.enable is the user's kill switch (settings →
+ * Speech); Config.options.speech.tts.endpoint, when set, overrides the
+ * server-mapped tts_url.
+ */
+Singleton {
+    id: root
+
+    readonly property bool enabled: Config.options?.speech?.tts?.enable ?? false
+    property bool speaking: synthProc.running || playProc.running
+    property string lastError: ""
+
+    property string _pendingText: ""
+    readonly property string _outFile: (Quickshell.env("XDG_RUNTIME_DIR") || "/tmp") + "/souveraine-speech.mp3"
+
+    // speak — synthesize and play `text` in the agent's voice. A new call
+    // replaces any in-flight synthesis or playback.
+    function speak(text) {
+        const t = String(text ?? "").trim();
+        if (t.length === 0 || !root.enabled) return;
+        stop();
+        root.lastError = "";
+        root._pendingText = t;
+        voiceLookup.running = true;
+    }
+
+    function stop() {
+        voiceLookup.running = false;
+        synthProc.running = false;
+        playProc.running = false;
+    }
+
+    // ── who → voice, from souveraine ─────────────────────────────────────
+    Process {
+        id: voiceLookup
+        command: ["curl", "-sf", "--max-time", "3", `${Souveraine.serverBase}/v1/config`]
+        stdout: StdioCollector {
+            onStreamFinished: {
+                let ttsUrl = Config.options?.speech?.tts?.endpoint ?? "";
+                let voice = "";
+                try {
+                    const cfg = JSON.parse(text);
+                    voice = cfg?.voice?.voice_id ?? "";
+                    if (ttsUrl.length === 0)
+                        ttsUrl = cfg?.voice?.tts_url ?? "";
+                } catch (e) {
+                    console.log("[Speech] could not parse /v1/config:", e);
+                }
+                if (ttsUrl.length === 0) {
+                    root.lastError = "no TTS endpoint (server unmapped, shell override empty)";
+                    console.log("[Speech]", root.lastError);
+                    return;
+                }
+                synthProc.command = [
+                    "curl", "-sf", "--max-time", "60",
+                    "-X", "POST", "-H", "Content-Type: application/json",
+                    "-d", JSON.stringify({
+                        input: root._pendingText,
+                        voice: voice,
+                        model: "vibevoice-v1"
+                    }),
+                    "-o", root._outFile,
+                    `${ttsUrl.replace(/\/$/, "")}/audio/speech`
+                ];
+                synthProc.running = true;
+            }
+        }
+        onExited: (exitCode) => {
+            if (exitCode !== 0) {
+                root.lastError = "souveraine server unreachable for voice mapping";
+                console.log("[Speech]", root.lastError);
+            }
+        }
+    }
+
+    // ── synthesis ────────────────────────────────────────────────────────
+    Process {
+        id: synthProc
+        onExited: (exitCode) => {
+            if (exitCode === 0) {
+                playProc.running = true;
+            } else {
+                root.lastError = `TTS synthesis failed (curl exit ${exitCode})`;
+                console.log("[Speech]", root.lastError);
+            }
+        }
+    }
+
+    // ── playback ─────────────────────────────────────────────────────────
+    Process {
+        id: playProc
+        command: ["sh", "-c",
+            `mpv --no-video --really-quiet '${root._outFile}' 2>/dev/null ` +
+            `|| ffplay -nodisp -autoexit -loglevel quiet '${root._outFile}'`]
+        onExited: (exitCode) => {
+            if (exitCode !== 0) {
+                root.lastError = `audio playback failed (exit ${exitCode}) — mpv/ffplay present?`;
+                console.log("[Speech]", root.lastError);
+            }
+        }
+    }
+}

surfaces/quickshell/services/qmldir

@@ -8,6 +8,7 @@ singleton Idle 1.0 Idle.qml
 singleton LockContentPolicy 1.0 LockContentPolicy.qml
 singleton NotifyEvents 1.0 NotifyEvents.qml
 singleton SessionAudit 1.0 SessionAudit.qml
+singleton Speech 1.0 Speech.qml
 singleton SessiondBridge 1.0 SessiondBridge.qml
 singleton SessionEvents 1.0 SessionEvents.qml
 singleton Souveraine 1.0 Souveraine.qml