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/file/list.go

@@ -0,0 +1,62 @@
+package fileapi
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	apitypes "github.com/yusing/go-proxy/internal/api/types"
+	"github.com/yusing/go-proxy/internal/common"
+	"github.com/yusing/go-proxy/internal/utils"
+)
+
+type ListFilesResponse struct {
+	Config     []string `json:"config"`
+	Provider   []string `json:"provider"`
+	Middleware []string `json:"middleware"`
+} // @name ListFilesResponse
+
+// @x-id				"list"
+// @BasePath		/api/v1
+// @Summary		List files
+// @Description	List files
+// @Tags			file
+// @Accept			json
+// @Produce		json
+// @Success		200	{object}	ListFilesResponse
+// @Failure		403	{object}	apitypes.ErrorResponse
+// @Failure		500	{object}	apitypes.ErrorResponse
+// @Router			/file/list [get]
+func List(c *gin.Context) {
+	resp := map[FileType][]string{
+		FileTypeConfig:     make([]string, 0),
+		FileTypeProvider:   make([]string, 0),
+		FileTypeMiddleware: make([]string, 0),
+	}
+
+	// config/
+	files, err := utils.ListFiles(common.ConfigBasePath, 0, true)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to list files"))
+		return
+	}
+
+	for _, file := range files {
+		t := GetFileType(file)
+		file = strings.TrimPrefix(file, common.ConfigBasePath+"/")
+		resp[t] = append(resp[t], file)
+	}
+
+	// config/middlewares/
+	mids, err := utils.ListFiles(common.MiddlewareComposeBasePath, 0, true)
+	if err != nil {
+		c.Error(apitypes.InternalServerError(err, "failed to list files"))
+		return
+	}
+	for _, mid := range mids {
+		mid = strings.TrimPrefix(mid, common.MiddlewareComposeBasePath+"/")
+		resp[FileTypeMiddleware] = append(resp[FileTypeMiddleware], mid)
+	}
+
+	c.JSON(http.StatusOK, resp)
+}