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/vaultik/verify.go

@@ -18,6 +18,20 @@ import (
 // VerifyOptions contains options for the verify command
 type VerifyOptions struct {
 	Deep bool
+	JSON bool
+}
+
+// VerifyResult contains the result of a snapshot verification
+type VerifyResult struct {
+	SnapshotID   string `json:"snapshot_id"`
+	Status       string `json:"status"` // "ok" or "failed"
+	Mode         string `json:"mode"`   // "shallow" or "deep"
+	BlobCount    int    `json:"blob_count"`
+	TotalSize    int64  `json:"total_size"`
+	Verified     int    `json:"verified"`
+	Missing      int    `json:"missing"`
+	MissingSize  int64  `json:"missing_size,omitempty"`
+	ErrorMessage string `json:"error,omitempty"`
 }
 
 // RunDeepVerify executes deep verification operation