refactor(api): migrate backend from Fiber v2 to v3

- Bump gofiber/fiber to v3.3.0 via fiber migrate CLI
- Swap contrib deps: otelfiber -> contrib/v3/otel, swagger -> contrib/v3/swaggo
- Update routing to v3 signature via new handler.register() helper
- Adapt cors.Config to []string fields with splitCommaEnv() helper
- *fiber.Ctx -> fiber.Ctx across handlers/middlewares

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: AchoArnold

api/pkg/di/config.go

@@ -3,6 +3,7 @@ package di
 import (
 	"log"
 	"os"
+	"strings"
 
 	"github.com/joho/godotenv"
 )
@@ -23,3 +24,15 @@ func getEnvWithDefault(key, defaultValue string) string {
 
 	return value
 }
+
+func splitCommaEnv(key, defaultValue string) []string {
+	value := getEnvWithDefault(key, defaultValue)
+	parts := strings.Split(value, ",")
+	result := make([]string, 0, len(parts))
+	for _, part := range parts {
+		if trimmed := strings.TrimSpace(part); trimmed != "" {
+			result = append(result, trimmed)
+		}
+	}
+	return result
+}

api/pkg/di/container.go

@@ -192,11 +192,11 @@ func (container *Container) App() (app *fiber.App) {
 	app.Use(
 		cors.New(
 			cors.Config{
-				AllowOrigins:     getEnvWithDefault("CORS_ALLOW_ORIGINS", "*"),
-				AllowHeaders:     getEnvWithDefault("CORS_ALLOW_HEADERS", "*"),
-				AllowMethods:     getEnvWithDefault("CORS_ALLOW_METHODS", "GET,POST,PUT,DELETE,OPTIONS"),
+				AllowOrigins:     splitCommaEnv("CORS_ALLOW_ORIGINS", "*"),
+				AllowHeaders:     splitCommaEnv("CORS_ALLOW_HEADERS", "*"),
+				AllowMethods:     splitCommaEnv("CORS_ALLOW_METHODS", "GET,POST,PUT,DELETE,OPTIONS"),
 				AllowCredentials: false,
-				ExposeHeaders:    getEnvWithDefault("CORS_EXPOSE_HEADERS", "*"),
+				ExposeHeaders:    splitCommaEnv("CORS_EXPOSE_HEADERS", "*"),
 			},
 		),
 	)

api/pkg/handlers/billing_handler.go

@@ -38,8 +38,8 @@ func NewBillingHandler(
 
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *BillingHandler) RegisterRoutes(router fiber.Router, middlewares ...fiber.Handler) {
-	router.Get("/v1/billing/usage-history", h.computeRoute(middlewares, h.UsageHistory)...)
-	router.Get("/v1/billing/usage", h.computeRoute(middlewares, h.Usage)...)
+	h.register(router, fiber.MethodGet, "/v1/billing/usage-history", middlewares, h.UsageHistory)
+	h.register(router, fiber.MethodGet, "/v1/billing/usage", middlewares, h.Usage)
 }
 
 // UsageHistory returns the usage history of a user

api/pkg/handlers/bulk_message_handler.go

@@ -46,8 +46,8 @@ func NewBulkMessageHandler(
 
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *BulkMessageHandler) RegisterRoutes(router fiber.Router, middlewares ...fiber.Handler) {
-	router.Get("/v1/bulk-messages", h.computeRoute(middlewares, h.Index)...)
-	router.Post("/v1/bulk-messages", h.computeRoute(middlewares, h.Store)...)
+	h.register(router, fiber.MethodGet, "/v1/bulk-messages", middlewares, h.Index)
+	h.register(router, fiber.MethodPost, "/v1/bulk-messages", middlewares, h.Store)
 }
 
 // Index fetches the bulk message order history.

api/pkg/handlers/discord_handler.go

@@ -57,13 +57,13 @@ func NewDiscordHandler(
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *DiscordHandler) RegisterRoutes(app *fiber.App, authMiddleware fiber.Handler, middlewares ...fiber.Handler) {
 	router := app.Group("discord")
-	router.Post("/event", h.computeRoute(middlewares, h.Event)...)
+	h.register(router, fiber.MethodPost, "/event", middlewares, h.Event)
 
 	authRouter := app.Group("v1/discord-integrations")
-	authRouter.Post("/", h.computeRoute(append(middlewares, authMiddleware), h.Store)...)
-	authRouter.Get("/", h.computeRoute(append(middlewares, authMiddleware), h.Index)...)
-	authRouter.Delete("/:discordID", h.computeRoute(append(middlewares, authMiddleware), h.Delete)...)
-	authRouter.Put("/:discordID", h.computeRoute(append(middlewares, authMiddleware), h.Update)...)
+	h.register(authRouter, fiber.MethodPost, "/", append(middlewares, authMiddleware), h.Store)
+	h.register(authRouter, fiber.MethodGet, "/", append(middlewares, authMiddleware), h.Index)
+	h.register(authRouter, fiber.MethodDelete, "/:discordID", append(middlewares, authMiddleware), h.Delete)
+	h.register(authRouter, fiber.MethodPut, "/:discordID", append(middlewares, authMiddleware), h.Update)
 }
 
 // Index returns the discord integrations of a user

api/pkg/handlers/events_handler.go

@@ -38,7 +38,7 @@ func NewEventsHandler(
 
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *EventsHandler) RegisterRoutes(router fiber.Router, middlewares ...fiber.Handler) {
-	router.Post("/v1/events", h.computeRoute(middlewares, h.Dispatch)...)
+	h.register(router, fiber.MethodPost, "/v1/events", middlewares, h.Dispatch)
 }
 
 // Dispatch a cloud event

api/pkg/handlers/handler.go

@@ -123,8 +123,13 @@ func (h *handler) userIDFomContext(c fiber.Ctx) entities.UserID {
 	return h.userFromContext(c).ID
 }
 
-func (h *handler) computeRoute(middlewares []fiber.Handler, route fiber.Handler) []fiber.Handler {
-	return append(append([]fiber.Handler{}, middlewares...), route)
+func (h *handler) register(router fiber.Router, method, path string, middlewares []fiber.Handler, route fiber.Handler) {
+	handlers := make([]any, 0, len(middlewares)+1)
+	for _, middleware := range middlewares {
+		handlers = append(handlers, middleware)
+	}
+	handlers = append(handlers, route)
+	router.Add([]string{method}, path, handlers[0], handlers[1:]...)
 }
 
 func (h *handler) mergeErrors(errors ...url.Values) url.Values {

api/pkg/handlers/heartbeat_handler.go

@@ -41,12 +41,12 @@ func NewHeartbeatHandler(
 
 // RegisterRoutes registers the routes for the HeartbeatHandler
 func (h *HeartbeatHandler) RegisterRoutes(router fiber.Router, middlewares ...fiber.Handler) {
-	router.Get("/v1/heartbeats", h.computeRoute(middlewares, h.Index)...)
+	h.register(router, fiber.MethodGet, "/v1/heartbeats", middlewares, h.Index)
 }
 
 // RegisterPhoneAPIKeyRoutes registers the routes for the HeartbeatHandler
 func (h *HeartbeatHandler) RegisterPhoneAPIKeyRoutes(router fiber.Router, middlewares ...fiber.Handler) {
-	router.Post("/v1/heartbeats", h.computeRoute(middlewares, h.Store)...)
+	h.register(router, fiber.MethodPost, "/v1/heartbeats", middlewares, h.Store)
 }
 
 // Index returns the heartbeats of a phone number

api/pkg/handlers/integration_3cx_handler.go

@@ -39,7 +39,7 @@ func NewIntegration3CxHandler(
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *Integration3CXHandler) RegisterRoutes(app *fiber.App, middlewares ...fiber.Handler) {
 	router := app.Group("integration/3cx/")
-	router.Post("/messages", h.computeRoute(middlewares, h.Messages)...)
+	h.register(router, fiber.MethodPost, "/messages", middlewares, h.Messages)
 }
 
 // Messages consumes a 3cx event

api/pkg/handlers/lemonsqueezy_handler.go

@@ -41,7 +41,7 @@ func NewLemonsqueezyHandler(
 // RegisterRoutes registers the routes for the MessageHandler
 func (h *LemonsqueezyHandler) RegisterRoutes(app *fiber.App, middlewares ...fiber.Handler) {
 	router := app.Group("lemonsqueezy")
-	router.Post("/event", h.computeRoute(middlewares, h.Event)...)
+	h.register(router, fiber.MethodPost, "/event", middlewares, h.Event)
 }
 
 // Event handles lemonsqueezy events