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

agent/pkg/handler/check_health.go

@@ -8,6 +8,7 @@ import (
 	"os"
 	"strings"
 
+	"github.com/yusing/go-proxy/internal/types"
 	"github.com/yusing/go-proxy/internal/watcher/health"
 	"github.com/yusing/go-proxy/internal/watcher/health/monitor"
 )
@@ -22,7 +23,7 @@ func CheckHealth(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var result *health.HealthCheckResult
+	var result *types.HealthCheckResult
 	var err error
 	switch scheme {
 	case "fileserver":
@@ -32,7 +33,7 @@ func CheckHealth(w http.ResponseWriter, r *http.Request) {
 			return
 		}
 		_, err := os.Stat(path)
-		result = &health.HealthCheckResult{Healthy: err == nil}
+		result = &types.HealthCheckResult{Healthy: err == nil}
 		if err != nil {
 			result.Detail = err.Error()
 		}