feat: add object versioning support

Implements object versioning capabilities (v0.15.0) including:
- Bucket APIs: PutBucketVersioning, GetBucketVersioning
- Object Listing: ListVersions (lists versions and delete markers)
- Object Operations: Updated FileDownload, FileDelete, and FileDetails to support VersionId
- Integration tests covering the full versioning workflow (enable, upload versions, list, download specific version, delete specific version)

Documentation updated in README.md and ROADMAP.md.

"I have implemented Object Versioning (v0.15.0) as per the roadmap."

object.go

@@ -21,12 +21,14 @@ import (
 type DownloadInput struct {
 	Bucket    string
 	ObjectKey string
+	VersionId string // Optional: Version ID of the object to download
 }
 
 // DetailsInput is passed to FileDetails as a parameter.
 type DetailsInput struct {
 	Bucket    string
 	ObjectKey string
+	VersionId string // Optional: Version ID of the object to retrieve details for
 }
 
 // DetailsResponse is returned by FileDetails.
@@ -93,13 +95,27 @@ type PutResponse struct {
 type DeleteInput struct {
 	Bucket    string
 	ObjectKey string
+	VersionId string // Optional: Version ID of the object to delete
 }
 
 // FileDownload makes a GET call and returns a io.ReadCloser.
 // After reading the response body, ensure closing the response.
 func (s3 *S3) FileDownload(u DownloadInput) (io.ReadCloser, error) {
+	urlStr := s3.getURL(u.Bucket, u.ObjectKey)
+
+	if u.VersionId != "" {
+		parsed, err := url.Parse(urlStr)
+		if err != nil {
+			return nil, err
+		}
+		q := parsed.Query()
+		q.Set("versionId", u.VersionId)
+		parsed.RawQuery = q.Encode()
+		urlStr = parsed.String()
+	}
+
 	req, err := http.NewRequest(
-		http.MethodGet, s3.getURL(u.Bucket, u.ObjectKey), nil,
+		http.MethodGet, urlStr, nil,
 	)
 	if err != nil {
 		return nil, err
@@ -315,8 +331,21 @@ func (s3 *S3) FileUpload(u UploadInput) (UploadResponse, error) {
 // FileDelete makes a DELETE call with the file written as multipart
 // and on successful upload, checks for 204 No Content.
 func (s3 *S3) FileDelete(u DeleteInput) error {
+	urlStr := s3.getURL(u.Bucket, u.ObjectKey)
+
+	if u.VersionId != "" {
+		parsed, err := url.Parse(urlStr)
+		if err != nil {
+			return err
+		}
+		q := parsed.Query()
+		q.Set("versionId", u.VersionId)
+		parsed.RawQuery = q.Encode()
+		urlStr = parsed.String()
+	}
+
 	req, err := http.NewRequest(
-		http.MethodDelete, s3.getURL(u.Bucket, u.ObjectKey), nil,
+		http.MethodDelete, urlStr, nil,
 	)
 	if err != nil {
 		return err
@@ -351,8 +380,21 @@ func (s3 *S3) FileDelete(u DeleteInput) error {
 }
 
 func (s3 *S3) FileDetails(u DetailsInput) (DetailsResponse, error) {
+	urlStr := s3.getURL(u.Bucket, u.ObjectKey)
+
+	if u.VersionId != "" {
+		parsed, err := url.Parse(urlStr)
+		if err != nil {
+			return DetailsResponse{}, err
+		}
+		q := parsed.Query()
+		q.Set("versionId", u.VersionId)
+		parsed.RawQuery = q.Encode()
+		urlStr = parsed.String()
+	}
+
 	req, err := http.NewRequest(
-		http.MethodHead, s3.getURL(u.Bucket, u.ObjectKey), nil,
+		http.MethodHead, urlStr, nil,
 	)
 	if err != nil {
 		return DetailsResponse{}, err