fix: handle registry errors gracefully (#1732)

We need to be able to handle stale registry entries gracefully. More
needs to be done when we are deleting important attributes from
resources which could have been persisted. But at the very least, the
server cannot die.

## Test Plan

Added unit tests

llama_stack/distribution/store/registry.py

@@ -12,9 +12,12 @@ import pydantic
 
 from llama_stack.distribution.datatypes import KVStoreConfig, RoutableObjectWithProvider
 from llama_stack.distribution.utils.config_dirs import DISTRIBS_BASE_DIR
+from llama_stack.log import get_logger
 from llama_stack.providers.utils.kvstore import KVStore, kvstore_impl
 from llama_stack.providers.utils.kvstore.config import SqliteKVStoreConfig
 
+logger = get_logger(__name__, category="core")
+
 
 class DistributionRegistry(Protocol):
     async def get_all(self) -> List[RoutableObjectWithProvider]: ...
@@ -47,8 +50,13 @@ def _parse_registry_values(values: List[str]) -> List[RoutableObjectWithProvider
     """Utility function to parse registry values into RoutableObjectWithProvider objects."""
     all_objects = []
     for value in values:
-        obj = pydantic.TypeAdapter(RoutableObjectWithProvider).validate_json(value)
-        all_objects.append(obj)
+        try:
+            obj = pydantic.TypeAdapter(RoutableObjectWithProvider).validate_json(value)
+            all_objects.append(obj)
+        except pydantic.ValidationError as e:
+            logger.error(f"Error parsing registry value, raw value: {value}. Error: {e}")
+            continue
+
     return all_objects
 
 
@@ -73,7 +81,11 @@ class DiskDistributionRegistry(DistributionRegistry):
         if not json_str:
             return None
 
-        return pydantic.TypeAdapter(RoutableObjectWithProvider).validate_json(json_str)
+        try:
+            return pydantic.TypeAdapter(RoutableObjectWithProvider).validate_json(json_str)
+        except pydantic.ValidationError as e:
+            logger.error(f"Error parsing registry value for {type}:{identifier}, raw value: {json_str}. Error: {e}")
+            return None
 
     async def update(self, obj: RoutableObjectWithProvider) -> None:
         await self.kvstore.set(