feat(backend): rouage gin /api/v1, enveloppe {data,meta}/{error}, health réel, stubs 501 + test de contrat routes

backend/pkg/api/response.go

@@ -0,0 +1,32 @@
+package api
+
+import "github.com/gin-gonic/gin"
+
+const NotImplementedCode = "NOT_IMPLEMENTED"
+
+type Meta struct {
+	Page     int `json:"page"`
+	PageSize int `json:"pageSize"`
+	Total    int `json:"total"`
+}
+
+func OK(c *gin.Context, data any) {
+	c.JSON(200, gin.H{"data": data})
+}
+
+func OKList(c *gin.Context, data any, page, pageSize, total int) {
+	c.JSON(200, gin.H{
+		"data": data,
+		"meta": Meta{Page: page, PageSize: pageSize, Total: total},
+	})
+}
+
+func Error(c *gin.Context, status int, code, message string) {
+	c.JSON(status, gin.H{
+		"error": gin.H{"code": code, "message": message},
+	})
+}
+
+func NotImplemented(c *gin.Context) {
+	Error(c, 501, NotImplementedCode, "route not implemented yet")
+}