refactor(tvix/castore): move *Node and Directory to crate root

*Node and Directory are types of the tvix-castore model, not the tvix
DirectoryService model. A DirectoryService only happens to send
Directories.

Move types into individual files in a nodes/ subdirectory, as it's
gotten too cluttered in a single file, and (re-)export all types from
the crate root.

This has the effect that we now cannot poke at private fields directly
from other files inside `crate::directoryservice` (as it's not all in
the same file anymore), but that's a good thing, it now forces us to go
through the proper accessors.

For the same reasons, we currently also need to introduce the `rename`
functions on each *Node directly.

A followup is gonna move the names out of the individual enum kinds, so
we can better represent "unnamed nodes".

Change-Id: Icdb34dcfe454c41c94f2396e8e99973d27db8418
Reviewed-on: https://cl.tvl.fyi/c/depot/+/12199
Reviewed-by: yuka <yuka@yuka.dev>
Autosubmit: flokli <flokli@flokli.de>
Tested-by: BuildkiteCI

tvix/glue/src/builtins/derivation.rs

@@ -179,7 +179,7 @@ pub(crate) mod derivation_builtins {
     use nix_compat::nixhash::CAHash;
     use nix_compat::store_path::{build_ca_path, hash_placeholder};
     use sha2::Sha256;
-    use tvix_castore::directoryservice::{FileNode, Node};
+    use tvix_castore::{FileNode, Node};
     use tvix_eval::generators::Gen;
     use tvix_eval::{NixContext, NixContextElement, NixString};
     use tvix_store::proto::{NarInfo, PathInfo};

tvix/glue/src/builtins/import.rs

@@ -2,9 +2,8 @@
 
 use crate::builtins::errors::ImportError;
 use std::path::Path;
-use tvix_castore::directoryservice::FileNode;
-use tvix_castore::directoryservice::Node;
 use tvix_castore::import::ingest_entries;
+use tvix_castore::{FileNode, Node};
 use tvix_eval::{
     builtin_macros::builtins,
     generators::{self, GenCo},

tvix/glue/src/fetchers/mod.rs

@@ -11,9 +11,7 @@ use tokio_util::io::{InspectReader, InspectWriter};
 use tracing::{instrument, warn, Span};
 use tracing_indicatif::span_ext::IndicatifSpanExt;
 use tvix_castore::{
-    blobservice::BlobService,
-    directoryservice::{DirectoryService, FileNode, Node},
-    ValidateNodeError,
+    blobservice::BlobService, directoryservice::DirectoryService, FileNode, Node, ValidateNodeError,
 };
 use tvix_store::{nar::NarCalculationService, pathinfoservice::PathInfoService, proto::PathInfo};
 use url::Url;

tvix/glue/src/tvix_build.rs

@@ -10,7 +10,7 @@ use tvix_build::proto::{
     build_request::{AdditionalFile, BuildConstraints, EnvVar},
     BuildRequest,
 };
-use tvix_castore::directoryservice::Node;
+use tvix_castore::Node;
 
 /// These are the environment variables that Nix sets in its sandbox for every
 /// build.
@@ -197,8 +197,8 @@ mod test {
         build_request::{AdditionalFile, BuildConstraints, EnvVar},
         BuildRequest,
     };
-    use tvix_castore::directoryservice::{DirectoryNode, Node};
     use tvix_castore::fixtures::DUMMY_DIGEST;
+    use tvix_castore::{DirectoryNode, Node};
 
     use crate::tvix_build::NIX_ENVIRONMENT_VARS;
 

tvix/glue/src/tvix_store_io.rs

@@ -20,7 +20,8 @@ use tvix_store::nar::NarCalculationService;
 
 use tvix_castore::{
     blobservice::BlobService,
-    directoryservice::{self, DirectoryService, NamedNode, Node},
+    directoryservice::{self, DirectoryService},
+    {NamedNode, Node},
 };
 use tvix_store::{pathinfoservice::PathInfoService, proto::PathInfo};