refactor(api): restructured API for type safety, maintainability and docs generation

- These changes makes the API incombatible with previous versions
- Added new types for error handling, success responses, and health checks.
- Updated health check logic to utilize the new types for better clarity and structure.
- Refactored existing handlers to improve response consistency and error handling.
- Updated Makefile to include a new target for generating API types from Swagger.
- Updated "new agent" API to respond an encrypted cert pair

internal/api/v1/version.go

@@ -0,0 +1,21 @@
+package v1
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+	"github.com/yusing/go-proxy/pkg"
+)
+
+// @x-id				"version"
+// @BasePath		/api/v1
+// @Summary		Get version
+// @Description	Get the version of the GoDoxy
+// @Tags			v1
+// @Accept			json
+// @Produce		plain
+// @Success		200	{string}	string	"version"
+// @Router			/version [get]
+func Version(c *gin.Context) {
+	c.JSON(http.StatusOK, pkg.GetVersion().String())
+}