feat: Add carrier-connector handler package with carrier info, connectivity check, and shared types for GSMA ES2+ profile management

- Add handlers package with GetCarrierInfoHandler returning static carrier name/mcc/mnc/smdpUrl/supported/lastChecked from environment config
- Add CheckConnectivityHandler with ES2+ GetProfileStatus probe using synthetic EID/ICCID and smdpConnected/checkedAt/error response
- Add ProfileOrder struct with EID/ICCID/IMSI/K/OPc/MCC/MNC/ProfileType/ConfirmationCode fields

apps/carrier-connector/internal/handler/handlers.go

@@ -0,0 +1,72 @@
+// Package handlers hosts HTTP handlers for the carrier-connector service.
+//
+// Profile handlers (order, get, list, delete) live in profile_handlers.go and
+// take a repository.ProfileRepository so profile state can be persisted and
+// queried. Carrier-level handlers (info, connectivity) that only touch the
+// ES2+ client live here.
+package handlers
+
+import (
+	"context"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/nutcas3/telecom-platform/apps/carrier-connector/internal/es2"
+)
+
+// GetCarrierInfoHandler returns static carrier information from environment config.
+func GetCarrierInfoHandler(_ *es2.ES2Client) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		c.JSON(http.StatusOK, gin.H{
+			"success": true,
+			"carrier": gin.H{
+				"name":        GetEnv("CARRIER_NAME", "Example Carrier"),
+				"mcc":         GetEnv("CARRIER_MCC", "208"),
+				"mnc":         GetEnv("CARRIER_MNC", "93"),
+				"smdpUrl":     GetEnv("SMDP_URL", "https://smdp.example.com"),
+				"supported":   true,
+				"lastChecked": time.Now().UTC(),
+			},
+		})
+	}
+}
+
+// CheckConnectivityHandler probes the SM-DP+ via an ES2+ GetProfileStatus call
+// with synthetic identifiers. A non-error response indicates the endpoint is
+// reachable and accepting authenticated requests.
+func CheckConnectivityHandler(client *es2.ES2Client) gin.HandlerFunc {
+	return func(c *gin.Context) {
+		req := &es2.GetProfileStatusRequest{EID: "connectivity-probe", ICCID: "connectivity-probe"}
+		_, err := client.GetProfileStatus(context.Background(), req)
+
+		connected := err == nil
+		var errMsg interface{}
+		if err != nil {
+			errMsg = err.Error()
+		}
+
+		c.JSON(http.StatusOK, gin.H{
+			"success": true,
+			"connectivity": gin.H{
+				"smdpConnected": connected,
+				"checkedAt":     time.Now().UTC(),
+				"error":         errMsg,
+			},
+		})
+	}
+}
+
+// parsePositiveInt parses a positive integer from a string, returning fallback on failure.
+func parsePositiveInt(s string, fallback int) int {
+	if s == "" {
+		return fallback
+	}
+	n, err := strconv.Atoi(s)
+	if err != nil || n <= 0 {
+		return fallback
+	}
+	return n
+}

apps/carrier-connector/internal/handler/types.go

@@ -0,0 +1,39 @@
+package handlers
+
+import (
+	"os"
+
+	"github.com/rs/zerolog"
+)
+
+// Logger is the package-level logger, initialized by main.
+var Logger zerolog.Logger
+
+// ProfileOrder is the GSMA ES2+ profile order request accepted by the API.
+type ProfileOrder struct {
+	EID              string `json:"eid"`
+	ICCID            string `json:"iccid"`
+	IMSI             string `json:"imsi"`
+	K                string `json:"k"`
+	OPc              string `json:"opc"`
+	MCC              string `json:"mcc"`
+	MNC              string `json:"mnc"`
+	ProfileType      string `json:"profileType"`
+	ConfirmationCode string `json:"confirmationCode,omitempty"`
+}
+
+// ProfileResponse is the GSMA ES2+ profile order response returned by the API.
+type ProfileResponse struct {
+	ExecutionStatus string `json:"executionStatus"`
+	StatusMessage   string `json:"statusMessage"`
+	ProfileID       string `json:"profileId"`
+	ActivationCode  string `json:"activationCode,omitempty"`
+}
+
+// GetEnv returns the value of an environment variable or fallback if unset.
+func GetEnv(key, fallback string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return fallback
+}