Switch to UUID for sqlite db

trovedb/tree.py

@@ -9,6 +9,9 @@ only the data field — storage is the caller's concern.
 import json
 
 
+from .trove import ObjectId
+
+
 class Tree:
     def __init__(self, data: bytes | None = None):
         """
@@ -16,7 +19,7 @@ class Tree:
         An empty Tree is created if data is None.
         """
         if not data:
-            self._entries: dict[str, int] = {}
+            self._entries: dict[str, ObjectId] = {}
         else:
             self._entries = json.loads(data.decode("utf-8"))
 
@@ -24,11 +27,11 @@ class Tree:
         """Serialize the tree to UTF-8 JSON bytes."""
         return json.dumps(self._entries).encode("utf-8")
 
-    def set_entry(self, name: str, object_id: int) -> None:
+    def set_entry(self, name: str, object_id: ObjectId) -> None:
         """Add or update an entry mapping name -> uuid."""
         self._entries[name] = object_id
 
-    def get_entry(self, name: str) -> int:
+    def get_entry(self, name: str) -> ObjectId:
         """Get the uuid associated with a name, or raise KeyError if not found."""
         return self._entries[name]
 
@@ -36,6 +39,6 @@ class Tree:
         """Remove an entry by name. Raises KeyError if not found."""
         del self._entries[name]
 
-    def list(self) -> dict[str, int]:
+    def list(self) -> dict[str, ObjectId]:
         """Return a shallow copy of all entries as {name: uuid}."""
         return dict(self._entries)