diff --git a/src/plyngent/config/store.py b/src/plyngent/config/store.py
index 32b32fa..1e29316 100644
--- a/src/plyngent/config/store.py
+++ b/src/plyngent/config/store.py
@@ -9,7 +9,7 @@ import tomlkit
 from .models import DatabaseConfig, Provider
 
 if TYPE_CHECKING:
-    from collections.abc import Mapping
+    from collections.abc import Mapping, MutableMapping
     from pathlib import Path
 
 
@@ -132,6 +132,12 @@ class ConfigStore:
 
     # -- internal sync helpers --
 
+    def _toml_table(self, key: str) -> MutableMapping[str, object]:
+        """Return a mutable table for ``key``, creating it if missing."""
+        if key not in self._document:
+            self._document[key] = tomlkit.table()
+        return cast("MutableMapping[str, object]", self._document[key])
+
     def _sync_database_section(self) -> None:
         """Sync ``[database]`` to the document."""
         raw_db: dict[str, object] = msgspec.to_builtins(self._database)
@@ -140,35 +146,30 @@ class ConfigStore:
                 del self._document["database"]
             return
 
-        if "database" not in self._document:
-            self._document["database"] = tomlkit.table()
-        section = self._document["database"]
-
-        for k in list(section.keys()):  # type: ignore[union-attr]
+        section = self._toml_table("database")
+        for k in list(section.keys()):
             if k not in raw_db:
-                del section[k]  # type: ignore[union-attr]
+                del section[k]
         for k, v in raw_db.items():
-            section[k] = v  # type: ignore[union-attr]
+            section[k] = v
 
     def _sync_providers_section(self) -> None:
         """Sync ``[providers]`` to the document."""
-        if "providers" not in self._document:
-            self._document["providers"] = tomlkit.table()
-        section = self._document["providers"]
+        section = self._toml_table("providers")
 
-        for name in list(section.keys()):  # type: ignore[union-attr]
+        for name in list(section.keys()):
             if name not in self._providers:
-                del section[name]  # type: ignore[union-attr]
+                del section[name]
 
         for name, provider in self._providers.items():
             raw: dict[str, object] = msgspec.to_builtins(provider)
             if name in section:
-                entry = section[name]  # type: ignore[union-attr]
-                entry.clear()  # type: ignore[union-attr]
+                entry = cast("MutableMapping[str, object]", section[name])
+                entry.clear()
                 for k, v in raw.items():
-                    entry[k] = v  # type: ignore[union-attr]
+                    entry[k] = v
             else:
-                section[name] = raw  # type: ignore[union-attr]
+                section[name] = raw
 
     def _sync_to_document(self) -> None:
         """Incrementally sync all sections into the document."""
diff --git a/tests/test_agent/test_loop.py b/tests/test_agent/test_loop.py
index df218c5..0374c87 100644
--- a/tests/test_agent/test_loop.py
+++ b/tests/test_agent/test_loop.py
@@ -63,9 +63,9 @@ class ScriptedClient:
         return self._responses.pop(0)
 
     async def _empty_stream(self) -> AsyncIterator[ChatCompletionChunk]:
-        if False:  # pyright: ignore[reportUnreachable]
-            yield  # type: ignore[misc]
-        return
+        empty: list[ChatCompletionChunk] = []
+        for chunk in empty:
+            yield chunk
 
 
 def _response(message: AssistantChatMessage) -> ChatCompletionResponse: