fix(growth): harden AI jobs and cost controls

internal/api/server.go

@@ -23,22 +23,33 @@ import (
 
 const maxExportBytes = 50 << 20
 
+const (
+	defaultGrowthSSECapacity     = 64
+	defaultGrowthSSEMaxDuration  = 5 * time.Minute
+	defaultGrowthSSEPollInterval = 2 * time.Second
+)
+
+var defaultGrowthSSESlots = make(chan struct{}, defaultGrowthSSECapacity)
+
 var errExportBytesExceeded = errors.New("export exceeds byte limit")
 
 type Server struct {
-	identity       *identity.Service
-	analytics      *analytics.Service
-	growth         growthReportService
-	logger         *slog.Logger
-	frontendOrigin string
-	cookieSecure   bool
+	identity              *identity.Service
+	analytics             *analytics.Service
+	growth                growthReportService
+	logger                *slog.Logger
+	frontendOrigin        string
+	cookieSecure          bool
+	growthSSESlots        chan struct{}
+	growthSSEMaxDuration  time.Duration
+	growthSSEPollInterval time.Duration
 }
 
 type sessionKey struct{}
 type tokenKey struct{}
 
 func NewServer(identityService *identity.Service, analyticsService *analytics.Service, logger *slog.Logger, frontendOrigin string, cookieSecure bool, growthService ...growthReportService) *Server {
-	server := &Server{identity: identityService, analytics: analyticsService, logger: logger, frontendOrigin: frontendOrigin, cookieSecure: cookieSecure}
+	server := &Server{identity: identityService, analytics: analyticsService, logger: logger, frontendOrigin: frontendOrigin, cookieSecure: cookieSecure, growthSSESlots: defaultGrowthSSESlots, growthSSEMaxDuration: defaultGrowthSSEMaxDuration, growthSSEPollInterval: defaultGrowthSSEPollInterval}
 	if len(growthService) > 0 {
 		server.growth = growthService[0]
 	}