feat(metrics): per-staff performance view in dashboard

GET /v1/metrics/staff returns bookings, completed, cancelled,
utilization, and revenue per staff member over a trailing window
(default 30d, max 365d). Appointment bookings only — class sessions
have no staff assignment. All active staff appear, including
zero-booking rows.

Staff page gains a localized Performance panel; demo mode seeds
trailing-window bookings and matching metric rows.

Generated with [Devin](https://devin.ai)

Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

packages/api-client/src/generated/types.ts

@@ -752,6 +752,26 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
+    "/v1/metrics/staff": {
+        parameters: {
+            query?: never;
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        /**
+         * Per-staff appointment metrics over a trailing window
+         * @description Bookings, completions, cancellations, utilization, and revenue per staff member. Only appointment bookings carry a staff assignment — class attendance is excluded by design. Every active staff member appears, including zero rows.
+         */
+        get: operations["getStaffMetrics"];
+        put?: never;
+        post?: never;
+        delete?: never;
+        options?: never;
+        head?: never;
+        patch?: never;
+        trace?: never;
+    };
     "/v1/public/bookings": {
         parameters: {
             query?: never;
@@ -1555,6 +1575,28 @@ export interface components {
             /** Format: uuid */
             tenantId: string;
         };
+        StaffMetric: {
+            bookings: number;
+            cancelled: number;
+            completed: number;
+            displayName: string;
+            /**
+             * Format: int64
+             * @description Sum of linked service prices for non-cancelled bookings
+             */
+            revenueCents: number;
+            /** Format: uuid */
+            staffId: string;
+            /** @description Share of bookings that stayed confirmed, 0-100 */
+            utilizationPercent: number;
+        };
+        StaffMetricsResponse: {
+            /** Format: date-time */
+            from: string;
+            staff: components["schemas"]["StaffMetric"][];
+            /** Format: date-time */
+            to: string;
+        };
         SubscriptionSnapshot: {
             cancelAtPeriodEnd: boolean;
             checkoutUrlAvailable: boolean;
@@ -3532,6 +3574,35 @@ export interface operations {
             };
         };
     };
+    getStaffMetrics: {
+        parameters: {
+            query?: {
+                days?: number;
+            };
+            header?: never;
+            path?: never;
+            cookie?: never;
+        };
+        requestBody?: never;
+        responses: {
+            /** @description Per-staff metrics */
+            200: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content: {
+                    "application/json": components["schemas"]["StaffMetricsResponse"];
+                };
+            };
+            /** @description Tenant membership not found */
+            404: {
+                headers: {
+                    [name: string]: unknown;
+                };
+                content?: never;
+            };
+        };
+    };
     createBooking: {
         parameters: {
             query?: never;