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/vaultik/remove_snapshot_test.go

@@ -291,7 +291,7 @@ func TestRemoveAllSnapshots_RequiresForce(t *testing.T) {
 
 	tv := vaultik.NewForTesting(store)
 
-	opts := &vaultik.RemoveOptions{All: true} // No Force
+	opts := &vaultik.RemoveOptions{} // No Force
 	_, err := tv.RemoveAllSnapshots(opts)
 
 	assert.Error(t, err)
@@ -310,7 +310,7 @@ func TestRemoveAllSnapshots_WithForce(t *testing.T) {
 
 	tv := vaultik.NewForTesting(store)
 
-	opts := &vaultik.RemoveOptions{All: true, Force: true}
+	opts := &vaultik.RemoveOptions{Force: true}
 	result, err := tv.RemoveAllSnapshots(opts)
 
 	require.NoError(t, err)
@@ -342,7 +342,7 @@ func TestRemoveAllSnapshots_DryRun(t *testing.T) {
 	// Default (no LocalOnly) enumerates the orphan remote keys, which
 	// matches what NewForTesting has — local DB is empty, so the two
 	// addManifest calls land as orphan remote keys.
-	opts := &vaultik.RemoveOptions{All: true, Force: true, DryRun: true}
+	opts := &vaultik.RemoveOptions{Force: true, DryRun: true}
 	result, err := tv.RemoveAllSnapshots(opts)
 
 	require.NoError(t, err)
@@ -362,7 +362,7 @@ func TestRemoveAllSnapshots_NoSnapshots(t *testing.T) {
 
 	tv := vaultik.NewForTesting(store)
 
-	opts := &vaultik.RemoveOptions{All: true, Force: true}
+	opts := &vaultik.RemoveOptions{Force: true}
 	result, err := tv.RemoveAllSnapshots(opts)
 
 	require.NoError(t, err)