Add --quiet flag, --json output, and config permission check

- Add global --quiet/-q flag to suppress non-error output
- Add --json flag to verify, snapshot rm, and prune commands
- Add config file permission check (warns if world/group readable)
- Update TODO.md to remove completed items

internal/cli/prune.go

@@ -19,10 +19,10 @@ func NewPruneCommand() *cobra.Command {
 		Short: "Remove unreferenced blobs",
 		Long: `Removes blobs that are not referenced by any snapshot.
 
-This command scans all snapshots and their manifests to build a list of 
+This command scans all snapshots and their manifests to build a list of
 referenced blobs, then removes any blobs in storage that are not in this list.
 
-Use this command after deleting snapshots with 'vaultik purge' to reclaim 
+Use this command after deleting snapshots with 'vaultik purge' to reclaim
 storage space.`,
 		Args: cobra.NoArgs,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -39,6 +39,7 @@ storage space.`,
 				LogOptions: log.LogOptions{
 					Verbose: rootFlags.Verbose,
 					Debug:   rootFlags.Debug,
+					Quiet:   rootFlags.Quiet || opts.JSON,
 				},
 				Modules: []fx.Option{},
 				Invokes: []fx.Option{
@@ -50,7 +51,9 @@ storage space.`,
 									// Run the prune operation
 									if err := v.PruneBlobs(opts); err != nil {
 										if err != context.Canceled {
-											log.Error("Prune operation failed", "error", err)
+											if !opts.JSON {
+												log.Error("Prune operation failed", "error", err)
+											}
 											os.Exit(1)
 										}
 									}
@@ -75,6 +78,7 @@ storage space.`,
 	}
 
 	cmd.Flags().BoolVar(&opts.Force, "force", false, "Skip confirmation prompt")
+	cmd.Flags().BoolVar(&opts.JSON, "json", false, "Output pruning stats as JSON")
 
 	return cmd
 }