lock: add FPC wiring preview

surfaces/quickshell/modules/common/Config.qml

@@ -481,6 +481,13 @@ Singleton {
                 // (background.wallpaperPath); a path pins the lock's own.
                 property string wallpaperPath: ""
                 property bool showLockedText: true
+                // A visible wiring exercise for the FPC1020 path. It is not
+                // biometric authentication: it may acknowledge a sensor pulse
+                // and a local hold, but it never unlocks or mints a grant.
+                property JsonObject fingerprintPreview: JsonObject {
+                    property bool enabled: false
+                    property int holdMs: 3000
+                }
                 // Souveraine-owned lock cards. Transport controls are
                 // ambient; media metadata remains personal by default.
                 property JsonObject content: JsonObject {

surfaces/quickshell/modules/common/panels/lock/LockContext.qml

@@ -23,6 +23,25 @@ Scope {
     property var targetAction: LockContext.ActionEnum.Unlock
     property bool alsoInhibitIdle: false
 
+    // This is deliberately an integration preview, not a biometric factor.
+    // The FPC1020's KEY_WAKEUP edge proves only that something asserted the
+    // line; it does not prove a matched enrolled fingerprint. Until the
+    // attested souveraine-fpd path exists, neither a pulse nor a touch hold
+    // may reach unlocked() or StepUpAuth.
+    readonly property bool provisionalFingerprintEnabled:
+        Config.options?.lock?.fingerprintPreview?.enabled ?? false
+    readonly property int provisionalFingerprintHoldMs:
+        Config.options?.lock?.fingerprintPreview?.holdMs ?? 3000
+    property bool provisionalFingerprintHolding: false
+    property bool provisionalFingerprintConfirmed: false
+    property bool provisionalFingerprintPulseSeen: false
+    property real provisionalFingerprintHoldProgress: 0
+    property double provisionalFingerprintHoldStartedAt: 0
+    property string provisionalFingerprintPulseToken: ""
+
+    signal provisionalFingerprintPulse()
+    signal provisionalFingerprintPreviewConfirmed()
+
     function resetTargetAction() {
         root.targetAction = LockContext.ActionEnum.Unlock;
     }
@@ -40,6 +59,111 @@ Scope {
         root.clearText();
         root.unlockInProgress = false;
         stopFingerPam();
+        root.resetProvisionalFingerprint();
+    }
+
+    function beginProvisionalFingerprintHold() {
+        if (!root.provisionalFingerprintEnabled) return;
+        root.provisionalFingerprintConfirmed = false;
+        root.provisionalFingerprintHolding = true;
+        root.provisionalFingerprintHoldStartedAt = Date.now();
+        root.provisionalFingerprintHoldProgress = 0;
+        provisionalFingerprintHoldTimer.start();
+    }
+
+    function cancelProvisionalFingerprintHold() {
+        if (!root.provisionalFingerprintHolding) return;
+        root.provisionalFingerprintHolding = false;
+        root.provisionalFingerprintHoldProgress = 0;
+        provisionalFingerprintHoldTimer.stop();
+    }
+
+    function confirmProvisionalFingerprintHold() {
+        if (!root.provisionalFingerprintHolding) return;
+        root.provisionalFingerprintHolding = false;
+        root.provisionalFingerprintHoldProgress = 1;
+        provisionalFingerprintHoldTimer.stop();
+        root.provisionalFingerprintConfirmed = true;
+        root.provisionalFingerprintPreviewConfirmed();
+        provisionalFingerprintConfirmTimer.restart();
+        console.log("[fingerprint-preview] hold confirmed; no authentication granted");
+    }
+
+    // Called by the narrow future producer seam (`fingerprint.signal`). This
+    // records only that an input path reached the surface. Any same-user IPC
+    // caller can cause this today, so it is intentionally visual-only.
+    function noteProvisionalFingerprintPulse() {
+        if (!root.provisionalFingerprintEnabled)
+            return { ok: false, code: "not_enabled", reason: "fingerprint preview is disabled" };
+        root.provisionalFingerprintPulseSeen = true;
+        root.provisionalFingerprintPulse();
+        provisionalFingerprintPulseTimer.restart();
+        console.log("[fingerprint-preview] pulse observed; no authentication granted");
+        return { ok: true, status: "observed" };
+    }
+
+    function resetProvisionalFingerprint() {
+        root.provisionalFingerprintHolding = false;
+        root.provisionalFingerprintConfirmed = false;
+        root.provisionalFingerprintPulseSeen = false;
+        root.provisionalFingerprintHoldProgress = 0;
+        provisionalFingerprintHoldTimer.stop();
+        provisionalFingerprintConfirmTimer.stop();
+        provisionalFingerprintPulseTimer.stop();
+    }
+
+    // blueline-fingerprintd is the only source that may write this root-owned
+    // status file. Its record says an FPC IRQ reached the daemon; it is not a
+    // match, and this listener has no authority beyond the preview pulse.
+    FileView {
+        id: provisionalFingerprintPulseFile
+        path: "/run/blueline-fingerprintd/preview-pulse"
+        watchChanges: true
+        printErrors: false
+        onFileChanged: reload()
+        onLoaded: {
+            try {
+                const record = JSON.parse(provisionalFingerprintPulseFile.text());
+                const token = `${record.sequence}:${record.at_ms}`;
+                if (token === root.provisionalFingerprintPulseToken) return;
+                root.provisionalFingerprintPulseToken = token;
+
+                // Do not replay an old event merely because the lock surface
+                // appeared after it. A new reader assertion has a fresh wall
+                // timestamp and reaches the same visual-only method as the IPC
+                // diagnostic seam.
+                const ageMs = Date.now() - Number(record.at_ms);
+                if (Number(record.sequence) > 0 && ageMs >= 0 && ageMs < 5000)
+                    root.noteProvisionalFingerprintPulse();
+            } catch (error) {
+                console.warn("[fingerprint-preview] invalid FPC pulse record:", error);
+            }
+        }
+    }
+
+    Timer {
+        id: provisionalFingerprintHoldTimer
+        interval: 50
+        repeat: true
+        onTriggered: {
+            const elapsed = Date.now() - root.provisionalFingerprintHoldStartedAt;
+            root.provisionalFingerprintHoldProgress = Math.min(1,
+                elapsed / Math.max(1, root.provisionalFingerprintHoldMs));
+            if (root.provisionalFingerprintHoldProgress >= 1)
+                root.confirmProvisionalFingerprintHold();
+        }
+    }
+
+    Timer {
+        id: provisionalFingerprintConfirmTimer
+        interval: 3500
+        onTriggered: root.provisionalFingerprintConfirmed = false
+    }
+
+    Timer {
+        id: provisionalFingerprintPulseTimer
+        interval: 3500
+        onTriggered: root.provisionalFingerprintPulseSeen = false
     }
 
     Timer {

surfaces/quickshell/modules/ii/lock/Lock.qml

@@ -97,6 +97,20 @@ LockScreen {
         }
     }
 
+    // Preview-only diagnostic ingress. The physical FPC1020 producer publishes
+    // its root-owned pulse record for LockContext to watch; it cannot use
+    // generic XF86WakeUp here because the touch controller emits that key too.
+    // This target lets us exercise the same visual-only path manually. It
+    // never unlocks, reveals Personal content, or mints step-up. Task 41 owns
+    // replacing this with an attested, source-specific producer.
+    IpcHandler {
+        target: "fingerprint"
+
+        function signal(): string {
+            return JSON.stringify(root.context.noteProvisionalFingerprintPulse());
+        }
+    }
+
     Timer {
         id: restoreTimer
         interval: 150

surfaces/quickshell/modules/ii/lock/TouchLockSurface.qml

@@ -193,6 +193,75 @@ MouseArea {
         TapHandler {
             onTapped: root.pinRevealed = true
         }
+
+        Item {
+            id: fingerprintPreview
+            Layout.alignment: Qt.AlignHCenter
+            Layout.topMargin: 18
+            visible: root.context.provisionalFingerprintEnabled
+            implicitWidth: 196
+            implicitHeight: 78
+
+            Rectangle {
+                anchors.fill: parent
+                radius: Appearance.rounding.normal
+                color: root.context.provisionalFingerprintConfirmed
+                    ? Appearance.colors.colPrimary
+                    : "#2a000000"
+                border.width: root.context.provisionalFingerprintPulseSeen ? 2 : 1
+                border.color: root.context.provisionalFingerprintPulseSeen
+                    ? Appearance.colors.colPrimary : "#66ffffff"
+            }
+
+            Rectangle {
+                anchors.left: parent.left
+                anchors.bottom: parent.bottom
+                width: parent.width * root.context.provisionalFingerprintHoldProgress
+                height: 3
+                radius: 2
+                color: Appearance.colors.colPrimary
+            }
+
+            ColumnLayout {
+                anchors.centerIn: parent
+                spacing: 2
+
+                MaterialSymbol {
+                    Layout.alignment: Qt.AlignHCenter
+                    text: "fingerprint"
+                    iconSize: 30
+                    color: root.context.provisionalFingerprintConfirmed
+                        ? Appearance.colors.colOnPrimary : Appearance.colors.colOnLayer1
+                }
+                StyledText {
+                    Layout.alignment: Qt.AlignHCenter
+                    text: root.context.provisionalFingerprintConfirmed
+                        ? Translation.tr("Hold recorded — PIN still required")
+                        : root.context.provisionalFingerprintPulseSeen
+                            ? Translation.tr("Sensor pulse received — hold to confirm")
+                            : Translation.tr("Hold %1 seconds to test fingerprint wiring")
+                                .arg(Math.round(root.context.provisionalFingerprintHoldMs / 1000))
+                    color: root.context.provisionalFingerprintConfirmed
+                        ? Appearance.colors.colOnPrimary : Appearance.colors.colSubtext
+                    font.pixelSize: Appearance.font.pixelSize.smaller
+                    horizontalAlignment: Text.AlignHCenter
+                }
+            }
+
+            MouseArea {
+                anchors.fill: parent
+                enabled: root.context.provisionalFingerprintEnabled
+                preventStealing: true
+                pressAndHoldInterval: root.context.provisionalFingerprintHoldMs
+                onPressed: {
+                    root.context.beginProvisionalFingerprintHold();
+                    mouse.accepted = true;
+                }
+                onReleased: root.context.cancelProvisionalFingerprintHold()
+                onCanceled: root.context.cancelProvisionalFingerprintHold()
+                onPressAndHold: root.context.confirmProvisionalFingerprintHold()
+            }
+        }
     }
 
     ColumnLayout {

surfaces/quickshell/modules/settings/LockConfig.qml

@@ -278,4 +278,33 @@ ContentPage {
             }
         }
     }
+
+    ContentSection {
+        icon: "fingerprint"
+        title: Translation.tr("Fingerprint integration")
+
+        ConfigSwitch {
+            buttonIcon: "fingerprint"
+            text: Translation.tr("Show fingerprint wiring preview")
+            checked: Config.options.lock.fingerprintPreview.enabled
+            onCheckedChanged: Config.options.lock.fingerprintPreview.enabled = checked
+            StyledToolTip {
+                text: Translation.tr("Shows a three-second hold test on the lock screen. It never unlocks the device or grants step-up; it is only the UI and sensor-routing preview.")
+            }
+        }
+
+        ConfigSpinBox {
+            icon: "timer"
+            text: Translation.tr("Preview hold (seconds)")
+            value: Config.options.lock.fingerprintPreview.holdMs / 1000
+            from: 1
+            to: 10
+            stepSize: 1
+            enabled: Config.options.lock.fingerprintPreview.enabled
+            onValueChanged: Config.options.lock.fingerprintPreview.holdMs = value * 1000
+            StyledToolTip {
+                text: Translation.tr("This controls only the visible hold exercise. A real fingerprint match must arrive through the attested FPC daemon before it can authenticate anything.")
+            }
+        }
+    }
 }