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

@@ -127,13 +127,13 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 		bar = progressbar.NewOptions64(
 			totalBytesExpected,
 			progressbar.OptionSetDescription("Restoring"),
-			progressbar.OptionSetWriter(os.Stderr),
+			progressbar.OptionSetWriter(v.Stderr),
 			progressbar.OptionShowBytes(true),
 			progressbar.OptionShowCount(),
 			progressbar.OptionSetWidth(40),
 			progressbar.OptionThrottle(100*time.Millisecond),
 			progressbar.OptionOnCompletion(func() {
-				fmt.Fprint(os.Stderr, "\n")
+				v.printfStderr("\n")
 			}),
 			progressbar.OptionSetRenderBlankState(true),
 		)
@@ -148,7 +148,11 @@ func (v *Vaultik) Restore(opts *RestoreOptions) error {
 			log.Error("Failed to restore file", "path", file.Path, "error", err)
 			result.FilesFailed++
 			result.FailedFiles = append(result.FailedFiles, file.Path.String())
-			// Continue with other files
+			// Update progress bar even on failure
+			if bar != nil {
+				_ = bar.Add64(file.Size)
+			}
+			continue
 		}
 
 		// Update progress bar