feat: add progress bar to restore operation

Add an interactive progress bar (using schollz/progressbar) to the
file restore loop, matching the existing pattern in verify. Shows
bytes restored with ETA when output is a terminal, falls back to
structured log progress every 100 files otherwise.

Fixes #20

internal/vaultik/restore.go

@@ -115,6 +115,30 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 	}
 	defer func() { _ = blobCache.Close() }()
 
+	// Calculate total bytes for progress bar
+	var totalBytesExpected int64
+	for _, file := range files {
+		totalBytesExpected += file.Size
+	}
+
+	// Create progress bar if output is a terminal
+	var bar *progressbar.ProgressBar
+	if isTerminal() {
+		bar = progressbar.NewOptions64(
+			totalBytesExpected,
+			progressbar.OptionSetDescription("Restoring"),
+			progressbar.OptionSetWriter(os.Stderr),
+			progressbar.OptionShowBytes(true),
+			progressbar.OptionShowCount(),
+			progressbar.OptionSetWidth(40),
+			progressbar.OptionThrottle(100*time.Millisecond),
+			progressbar.OptionOnCompletion(func() {
+				fmt.Fprint(os.Stderr, "\n")
+			}),
+			progressbar.OptionSetRenderBlankState(true),
+		)
+	}
+
 	for i, file := range files {
 		if v.ctx.Err() != nil {
 			return v.ctx.Err()
@@ -125,10 +149,14 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 			result.FilesFailed++
 			result.FailedFiles = append(result.FailedFiles, file.Path.String())
 			// Continue with other files
-			continue
 		}
 
-		// Progress logging
+		// Update progress bar
+		if bar != nil {
+			_ = bar.Add64(file.Size)
+		}
+
+		// Progress logging (for non-terminal or structured logs)
 		if (i+1)%100 == 0 || i+1 == len(files) {
 			log.Info("Restore progress",
 				"files", fmt.Sprintf("%d/%d", i+1, len(files)),
@@ -137,6 +165,10 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 		}
 	}
 
+	if bar != nil {
+		_ = bar.Finish()
+	}
+
 	result.Duration = time.Since(startTime)
 
 	log.Info("Restore complete",