chore: add golangci-lint v2 config and fix linter warnings (#46)

- [x] Add golangci-lint v2 configuration with formatters section
- [x] Reorganize linters-settings under linters section
- [x] Replace if-else chains with switch statements for clarity
- [x] Wrap all ignored error returns with `_ = ` pattern
- [x] Add OSC 8 hyperlink helper function for clickable ports
- [x] Add blank line in table styling function
- [x] Remove unnecessary type assertion in test

cmd/kportal/main.go

@@ -347,10 +347,11 @@ func main() {
 				}
 
 				// Populate headers based on direction
-				if entry.Direction == "request" {
+				switch entry.Direction {
+				case "request":
 					uiEntry.RequestHeaders = entry.Headers
 					uiEntry.RequestBody = entry.Body
-				} else if entry.Direction == "response" {
+				case "response":
 					uiEntry.ResponseHeaders = entry.Headers
 					uiEntry.ResponseBody = entry.Body
 				}