feat: scheduled report digests + per-session capacity (M33)

POST /v1/internal/jobs/reports/dispatch emails each tenant owner a
trailing-window digest (bookings, revenue, per-service and per-staff
breakdown) localized to the tenant locale; zero-activity tenants are
skipped. Metrics cores extracted to tenant-scoped variants so the job
needs no principal.

PATCH /v1/catalog/class-sessions/:id sets a session's seat count with
a confirmed-bookings floor — shrinking below it needs allowOverCapacity,
matching the waitlist-promotion convention. Session rows gain an inline
capacity editor with an overbook confirm state.

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

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

apps/backend/internal/api/server.go

@@ -25,6 +25,7 @@ import (
 	"bookra/apps/backend/internal/export"
 	"bookra/apps/backend/internal/httpx"
 	"bookra/apps/backend/internal/notifications"
+	"bookra/apps/backend/internal/reports"
 	"bookra/apps/backend/internal/sms"
 	"bookra/apps/backend/internal/tenancy"
 
@@ -65,6 +66,7 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 	authService := auth.NewService(repository, cfg.AuthJWTSecret)
 	adminService := admin.NewService(repository, cfg.AdminEmail, cfg.AdminKey)
 	smsService := sms.NewService(cfg, repository)
+	reportService := reports.NewService(repository, bookingService, cfg.FrontendURL, cfg.EmailFrom)
 	notificationService.SetSMSSender(func(ctx context.Context, tenantID, phone, body string) error {
 		_, err := smsService.SendMessage(ctx, tenantID, domain.SendSMSRequest{To: phone, Body: body})
 		return err
@@ -1103,6 +1105,28 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 		}
 		c.JSON(http.StatusOK, response)
 	})
+	protected.PATCH("/catalog/class-sessions/:sessionID", func(c *gin.Context) {
+		var request domain.UpdateClassSessionRequest
+		if err := c.ShouldBindJSON(&request); err != nil {
+			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid_request"})
+			return
+		}
+		response, err := catalogService.UpdateClassSession(c.Request.Context(), auth.PrincipalFromContext(c), c.Param("sessionID"), request)
+		if err != nil {
+			status := http.StatusInternalServerError
+			switch {
+			case errors.Is(err, catalog.ErrTenantMembership), errors.Is(err, catalog.ErrClassSessionNotFound):
+				status = http.StatusNotFound
+			case errors.Is(err, catalog.ErrInvalidInput):
+				status = http.StatusBadRequest
+			case errors.Is(err, catalog.ErrCapacityBelowBooked):
+				status = http.StatusConflict
+			}
+			c.JSON(status, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, response)
+	})
 	protected.DELETE("/catalog/class-sessions/:sessionID", func(c *gin.Context) {
 		err := catalogService.DeleteClassSession(c.Request.Context(), auth.PrincipalFromContext(c), c.Param("sessionID"))
 		if err != nil {
@@ -1697,6 +1721,23 @@ func NewServer(cfg config.Config, pools *db.Pools) (*Server, error) {
 		c.JSON(http.StatusOK, response)
 	})
 
+	server.router.POST("/v1/internal/jobs/reports/dispatch", func(c *gin.Context) {
+		if !authorizeJobRunner(c, cfg) {
+			c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
+			return
+		}
+		days, _ := strconv.Atoi(c.DefaultQuery("days", "7"))
+		response, err := reportService.DispatchDigests(c.Request.Context(), days, c.Query("tenantId"), func(ctx context.Context, msg notifications.EmailMessage) error {
+			_, sendErr := notificationService.SendRawEmail(ctx, msg)
+			return sendErr
+		})
+		if err != nil {
+			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+			return
+		}
+		c.JSON(http.StatusOK, response)
+	})
+
 	// Widget embeddable script endpoint - serves JavaScript for external sites
 	server.router.GET("/v1/public/widget.js", func(c *gin.Context) {
 		c.Header("Content-Type", "application/javascript; charset=utf-8")