feat(admin): feature flags CRUD with DB persistence

veza-backend-api/internal/api/routes_core.go

@@ -436,6 +436,12 @@ func (r *APIRouter) setupCoreProtectedRoutes(v1 *gin.RouterGroup) {
 		admin.POST("/announcements", announcementHandler.Create)
 		admin.DELETE("/announcements/:id", announcementHandler.Delete)
 
+		// v0.803 ADM1-05: Feature flags CRUD
+		featureFlagSvc := services.NewFeatureFlagService(r.db.GormDB, r.logger)
+		featureFlagHandler := handlers.NewFeatureFlagHandler(featureFlagSvc)
+		admin.GET("/feature-flags", featureFlagHandler.List)
+		admin.PUT("/feature-flags/:name", featureFlagHandler.Toggle)
+
 		// v0.701: Admin Transfer Dashboard
 		var adminTransferHandler *handlers.AdminTransferHandler
 		if r.config != nil && r.config.StripeConnectEnabled && r.config.StripeConnectSecretKey != "" {

veza-backend-api/internal/handlers/feature_flag_handler.go

@@ -0,0 +1,53 @@
+package handlers
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+
+	"veza-backend-api/internal/services"
+)
+
+// FeatureFlagHandler handles feature flag endpoints (v0.803 ADM1-05)
+type FeatureFlagHandler struct {
+	svc *services.FeatureFlagService
+}
+
+// NewFeatureFlagHandler creates a new FeatureFlagHandler
+func NewFeatureFlagHandler(svc *services.FeatureFlagService) *FeatureFlagHandler {
+	return &FeatureFlagHandler{svc: svc}
+}
+
+// List returns all feature flags (admin)
+func (h *FeatureFlagHandler) List(c *gin.Context) {
+	list, err := h.svc.List(c.Request.Context())
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to list feature flags"})
+		return
+	}
+	c.JSON(http.StatusOK, gin.H{"feature_flags": list})
+}
+
+// Toggle enables or disables a feature flag (admin)
+func (h *FeatureFlagHandler) Toggle(c *gin.Context) {
+	name := c.Param("name")
+	if name == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "name is required"})
+		return
+	}
+
+	var req struct {
+		Enabled bool `json:"enabled"`
+	}
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "enabled is required"})
+		return
+	}
+
+	flag, err := h.svc.Toggle(c.Request.Context(), name, req.Enabled)
+	if err != nil {
+		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
+		return
+	}
+	c.JSON(http.StatusOK, flag)
+}

veza-backend-api/internal/models/feature_flag.go

@@ -0,0 +1,18 @@
+package models
+
+import (
+	"time"
+)
+
+// FeatureFlag represents a feature flag (v0.803 ADM1-05)
+type FeatureFlag struct {
+	Name        string    `gorm:"primaryKey;size:100" json:"name"`
+	Enabled     bool      `gorm:"not null;default:false" json:"enabled"`
+	Description string    `gorm:"type:text" json:"description,omitempty"`
+	UpdatedAt  time.Time `gorm:"not null" json:"updated_at"`
+}
+
+// TableName returns the table name
+func (FeatureFlag) TableName() string {
+	return "feature_flags"
+}

veza-backend-api/internal/services/feature_flag_service.go

@@ -0,0 +1,49 @@
+package services
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"go.uber.org/zap"
+	"gorm.io/gorm"
+
+	"veza-backend-api/internal/models"
+)
+
+// FeatureFlagService handles feature flags (v0.803 ADM1-05)
+type FeatureFlagService struct {
+	db     *gorm.DB
+	logger *zap.Logger
+}
+
+// NewFeatureFlagService creates a new FeatureFlagService
+func NewFeatureFlagService(db *gorm.DB, logger *zap.Logger) *FeatureFlagService {
+	return &FeatureFlagService{db: db, logger: logger}
+}
+
+// List returns all feature flags
+func (s *FeatureFlagService) List(ctx context.Context) ([]models.FeatureFlag, error) {
+	var list []models.FeatureFlag
+	if err := s.db.WithContext(ctx).Order("name ASC").Find(&list).Error; err != nil {
+		return nil, fmt.Errorf("failed to list feature flags: %w", err)
+	}
+	return list, nil
+}
+
+// Toggle enables or disables a feature flag by name
+func (s *FeatureFlagService) Toggle(ctx context.Context, name string, enabled bool) (*models.FeatureFlag, error) {
+	var flag models.FeatureFlag
+	if err := s.db.WithContext(ctx).Where("name = ?", name).First(&flag).Error; err != nil {
+		if err == gorm.ErrRecordNotFound {
+			return nil, fmt.Errorf("feature flag not found: %s", name)
+		}
+		return nil, fmt.Errorf("failed to get feature flag: %w", err)
+	}
+	flag.Enabled = enabled
+	flag.UpdatedAt = time.Now()
+	if err := s.db.WithContext(ctx).Save(&flag).Error; err != nil {
+		return nil, fmt.Errorf("failed to update feature flag: %w", err)
+	}
+	return &flag, nil
+}

veza-backend-api/migrations/935_feature_flags.sql

@@ -0,0 +1,14 @@
+-- v0.803 ADM1-05: Feature flags with DB persistence
+CREATE TABLE IF NOT EXISTS feature_flags (
+    name VARCHAR(100) PRIMARY KEY,
+    enabled BOOLEAN NOT NULL DEFAULT false,
+    description TEXT,
+    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+INSERT INTO feature_flags (name, enabled, description) VALUES
+  ('HLS_STREAMING', true, 'Enable HLS streaming'),
+  ('ROLE_MANAGEMENT', true, 'Enable role management'),
+  ('PLAYLIST_SHARE', true, 'Enable playlist sharing'),
+  ('PLAYLIST_RECOMMENDATIONS', true, 'Enable playlist recommendations')
+ON CONFLICT (name) DO NOTHING;