Consolidate CLI verbs; retire overlapping commands

The verb surface accumulated overlapping cleanup commands. Consolidate
so each cleanup verb has one meaning:

- Rename 'database purge' -> 'database delete'. The command removes the
  SQLite file entirely; "purge" wrongly suggested purging contents.
- Fold 'snapshot cleanup' into 'prune'. Prune now runs three passes:
  reconcile local snapshots against the remote (previously the
  standalone cleanup command), drop orphaned local rows, then delete
  unreferenced remote blobs. One command, one mental model.
- Delete 'store info'. Its output was a strict subset of 'remote info',
  which already prints storage type + location. Any user reaching for
  either should reach for 'remote info'.
- Drop 'snapshot remove --all'. It duplicated 'remote nuke --force'.
  'remote nuke' is the single supported entry point for wiping the
  destination store.

Also update the storage-binding error message to reference the new
'vaultik database delete' name.

internal/cli/database.go

@@ -18,28 +18,33 @@ func NewDatabaseCommand() *cobra.Command {
 	}
 
 	cmd.AddCommand(
-		newDatabasePurgeCommand(),
+		newDatabaseDeleteCommand(),
 	)
 
 	return cmd
 }
 
-// newDatabasePurgeCommand creates the database purge command
-func newDatabasePurgeCommand() *cobra.Command {
+// newDatabaseDeleteCommand creates the database delete command.
+// (Renamed from "purge"; the operation removes the SQLite file
+// entirely, which is a delete, not a purge of content.)
+func newDatabaseDeleteCommand() *cobra.Command {
 	var force bool
 
 	cmd := &cobra.Command{
-		Use:   "purge",
-		Short: "Delete the local state database",
+		Use:   "delete",
+		Short: "Delete the local state database file",
 		Long: `Completely removes the local SQLite state database.
 
 This will erase all local tracking of:
 - File metadata and change detection state
 - Chunk and blob mappings
 - Local snapshot records
+- The storage-binding record
 
-The remote storage is NOT affected. After purging, the next backup will
-perform a full scan and re-deduplicate against existing remote blobs.
+The remote storage is NOT affected. After deletion, the next backup
+will perform a full scan and re-deduplicate against existing remote
+blobs, and the local index will re-bind to the currently configured
+storage destination on that run.
 
 Use --force to skip the confirmation prompt.`,
 		Args: cobra.NoArgs,
@@ -88,10 +93,10 @@ Use --force to skip the confirmation prompt.`,
 
 			rootFlags := GetRootFlags()
 			if !rootFlags.Quiet {
-				fmt.Printf("Database purged: %s\n", dbPath)
+				fmt.Printf("Database deleted: %s\n", dbPath)
 			}
 
-			log.Info("Local state database purged", "path", dbPath)
+			log.Info("Local state database deleted", "path", dbPath)
 			return nil
 		},
 	}