Collapse snapshot prune into vaultik prune; auto-clean on removal

The CLI had two commands named "prune" doing different jobs (local
DB orphan cleanup vs. remote blob garbage collection), which was
confusing and forced a manual two-step workflow after deleting any
snapshot.

Single user-facing prune surface is now `vaultik prune`, which calls
PruneDatabase (local orphan cleanup) then PruneBlobs (remote unref
blob GC). Snapshot deletion paths (snapshot remove, snapshot remove
--all, snapshot purge) auto-run CleanupOrphanedData inline so the
local index database doesn't accumulate ghost rows after every
removal — the user observed ~39k orphaned files and 2 orphaned blobs
after a remove --all because that cleanup was previously a separate
opt-in command. `snapshot prune` is removed.

Also addresses the doc/help-string drift the user audit caught:

  * cli/prune.go help text used to reference a non-existent
    `vaultik purge` command.
  * cli/config.go get/set short/long examples were S3-specific
    (s3.bucket) when the primary storage configuration is
    storage_url.
  * vaultik/info.go printed S3 Bucket/Endpoint/Region labels
    unconditionally; for file:// or rclone:// users those rows
    were empty. The Storage Configuration block now prints the
    storer's Type+Location first, the storage_url string when set,
    and only emits S3 rows that are actually populated.
  * vaultik/info.go's "Run 'vaultik prune --remote'" hint
    referenced a flag that doesn't exist.
  * vaultik/blobcache.go's doc comment claimed LRU eviction, which
    is no longer the restore-time policy (the sweeper drives
    eviction; LRU is the safety-net fallback when maxBytes is
    finite).
  * README.md listed `vaultik restore`, `vaultik snapshot prune`,
    and `s3.bucket` example, all out of date.

README's roadmap section is rewritten with concrete pre-1.0 items
(security audit, error-condition tests, parallel blob downloads,
restart of interrupted restore, …) so the next-steps surface
matches what the project actually still needs.

The cleanup calls are guarded against a nil SnapshotManager so
tests that construct a bare Vaultik struct continue to work.

internal/vaultik/snapshot.go

@@ -768,9 +768,18 @@ func (v *Vaultik) confirmAndExecutePurge(toDelete []SnapshotInfo, force, quiet b
 		}
 	}
 
+	// Tidy up local DB orphans now so users don't have to run a
+	// separate command after a purge. Guarded against nil for tests
+	// that don't wire up a SnapshotManager.
+	if v.SnapshotManager != nil {
+		if err := v.SnapshotManager.CleanupOrphanedData(v.ctx); err != nil {
+			log.Warn("Failed to clean up orphaned local data after purge", "error", err)
+		}
+	}
+
 	if !quiet {
 		v.printfStdout("Deleted %d snapshot(s)\n", len(toDelete))
-		v.printlnStdout("\nNote: Run 'vaultik prune' to clean up unreferenced blobs.")
+		v.printlnStdout("\nNote: Run 'vaultik prune' to clean up unreferenced remote blobs.")
 	}
 
 	return nil
@@ -1092,6 +1101,16 @@ func (v *Vaultik) RemoveSnapshot(snapshotID string, opts *RemoveOptions) (*Remov
 		result.RemoteRemoved = true
 	}
 
+	// Clean up the local rows that just became orphaned (files, chunks,
+	// blob_chunks, blobs no longer referenced by any snapshot). This
+	// used to be a separate `vaultik snapshot prune` step; running it
+	// inline means `snapshot remove` leaves no ghost rows behind.
+	if v.SnapshotManager != nil {
+		if err := v.SnapshotManager.CleanupOrphanedData(v.ctx); err != nil {
+			log.Warn("Failed to clean up orphaned local data after removal", "error", err)
+		}
+	}
+
 	// Output result
 	if opts.JSON {
 		return result, v.outputRemoveJSON(result)
@@ -1101,7 +1120,7 @@ func (v *Vaultik) RemoveSnapshot(snapshotID string, opts *RemoveOptions) (*Remov
 	v.printfStdout("Removed snapshot '%s' from local database\n", snapshotID)
 	if opts.Remote {
 		v.printlnStdout("Removed snapshot metadata from remote storage")
-		v.printlnStdout("\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
+		v.printlnStdout("\nNote: Remote blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
 	}
 
 	return result, nil
@@ -1213,6 +1232,14 @@ func (v *Vaultik) executeRemoveAll(snapshotIDs []string, opts *RemoveOptions) (*
 		result.RemoteRemoved = true
 	}
 
+	// Clean up everything that just became orphaned locally so the
+	// index database doesn't carry 39k ghost rows after a wipe.
+	if v.SnapshotManager != nil {
+		if err := v.SnapshotManager.CleanupOrphanedData(v.ctx); err != nil {
+			log.Warn("Failed to clean up orphaned local data after bulk removal", "error", err)
+		}
+	}
+
 	if opts.JSON {
 		return result, v.outputRemoveJSON(result)
 	}
@@ -1220,7 +1247,7 @@ func (v *Vaultik) executeRemoveAll(snapshotIDs []string, opts *RemoveOptions) (*
 	v.printfStdout("Removed %d snapshot(s)\n", len(result.SnapshotsRemoved))
 	if opts.Remote {
 		v.printlnStdout("Removed snapshot metadata from remote storage")
-		v.printlnStdout("\nNote: Blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
+		v.printlnStdout("\nNote: Remote blobs were not removed. Run 'vaultik prune' to remove orphaned blobs.")
 	}
 
 	return result, nil