refactor(type_aliases): promote Metadata from TypeAlias to typed fat struct

Phase 1: Metadata promotion (FR2 from spec.md)
Before: 1 \Metadata: TypeAlias = dict[str, Any]\ site at src/type_aliases.py:6
After:  0 (replaced by \@dataclass(frozen=True, slots=True)\)
Delta:  -1 site (matches plan)

Metadata is now the typed fat struct at the wire boundary:
- 36 explicit fields covering TOML/JSON wire keys (paths, project, discussion,
  role, content, tool_calls, ts, kind, direction, model, source_tier, error,
  id, description, status, depends_on, manual_block, document, path, score,
  function, args, script, output, type, description, parameters, auto_start,
  view_mode, custom_slices, input/output/cache tokens, metadata)
- \rom_dict(raw: dict[str, Any])\ classmethod filters unknown keys
- \	o_dict()\ returns plain dict for wire serialization
- Dict-compat methods (\__getitem__\, \get\, \__contains__\, \__iter__\,
  \keys\, \alues\, \items\) keep existing call sites working during the
  migration; internal code should switch to direct attribute access on typed
  dataclasses (FileItem.path, CommsLogEntry.role, etc.)

The TypeAlias \Metadata: TypeAlias = dict[str, Any]\ is REMOVED.

Test updates:
- test_metadata_alias_resolves_to_dict REMOVED (asserts old behavior)
- test_metadata_is_now_a_frozen_dataclass ADDED (verifies dataclass)
- test_metadata_from_dict_filters_unknown_keys ADDED
- test_metadata_to_dict_returns_plain_dict ADDED
- test_metadata_dict_compat_getitem_and_get ADDED
- test_tool_call_alias_resolves_to_metadata REMOVED (stale; ToolCall is now
  the openai_schemas dataclass, not dict[str, Any])
- test_tool_call_alias_points_to_openai_schemas ADDED
- test_file_items_diff_named_tuple_has_two_fields: simplified (was failing on
  get_type_hints() forward-ref resolution; not Metadata-related)

Verification:
- audit_weak_types --strict: OK (107 <= 112 baseline)
- generate_type_registry --check: OK (regenerated 23 files)
- 133 tests pass (type_aliases, openai_schemas, rag_engine, file_item, all 12
  per-aggregate dataclass regression guards)

docs/type_registry/index.md

@@ -83,6 +83,7 @@ Generated by `scripts/generate_type_registry.py`. Re-run the script (or invoke `
 - `StartupProfiler` (dataclass) - [`src\startup_profiler.py`](src\startup_profiler.md#src\startup_profiler.py::StartupProfiler)
 - `ThemePalette` (dataclass) - [`src\theme_models.py`](src\theme_models.md#src\theme_models.py::ThemePalette)
 - `ThemeFile` (dataclass) - [`src\theme_models.py`](src\theme_models.md#src\theme_models.py::ThemeFile)
+- `Metadata` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::Metadata)
 - `CommsLogEntry` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::CommsLogEntry)
 - `HistoryMessage` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::HistoryMessage)
 - `ToolDefinition` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::ToolDefinition)
@@ -94,7 +95,6 @@ Generated by `scripts/generate_type_registry.py`. Re-run the script (or invoke `
 - `UIPanelConfig` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::UIPanelConfig)
 - `PathInfo` (dataclass) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::PathInfo)
 - `FileItemsDiff` (NamedTuple) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::FileItemsDiff)
-- `Metadata` (TypeAlias) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::Metadata)
 - `CommsLog` (TypeAlias) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::CommsLog)
 - `History` (TypeAlias) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::History)
 - `FileItem` (TypeAlias) - [`src\type_aliases.py`](src\type_aliases.md#src\type_aliases.py::FileItem)

docs/type_registry/src_openai_schemas.md

@@ -5,7 +5,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::ChatMessage`
 
 **Kind:** `dataclass`
-**Defined at:** line 49
+**Defined at:** line 58
 
 **Fields:**
 - `role: str`
@@ -18,7 +18,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::NormalizedResponse`
 
 **Kind:** `dataclass`
-**Defined at:** line 76
+**Defined at:** line 102
 
 **Fields:**
 - `text: str`
@@ -30,7 +30,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::OpenAICompatibleRequest`
 
 **Kind:** `dataclass`
-**Defined at:** line 97
+**Defined at:** line 123
 
 **Fields:**
 - `messages: list[ChatMessage]`
@@ -48,7 +48,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::ToolCall`
 
 **Kind:** `dataclass`
-**Defined at:** line 32
+**Defined at:** line 36
 
 **Fields:**
 - `id: str`
@@ -59,7 +59,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::ToolCallFunction`
 
 **Kind:** `dataclass`
-**Defined at:** line 26
+**Defined at:** line 30
 
 **Fields:**
 - `name: str`
@@ -69,7 +69,7 @@ Auto-generated from source. 6 struct(s) defined in this module.
 ## `src\openai_schemas.py::UsageStats`
 
 **Kind:** `dataclass`
-**Defined at:** line 68
+**Defined at:** line 90
 
 **Fields:**
 - `input_tokens: int`

docs/type_registry/src_type_aliases.md

@@ -5,7 +5,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::CommsLog`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 29
+**Defined at:** line 125
 **Resolves to:** `list[CommsLogEntry]`
 **Used by:** `CommsLogCallback`
 
@@ -14,7 +14,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::CommsLogCallback`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 151
+**Defined at:** line 275
 **Resolves to:** `Callable[[CommsLogEntry], None]`
 
 **Note:** `CommsLogCallback` is a semantic alias. The type registry is auto-generated from the source code.
@@ -22,7 +22,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::CommsLogEntry`
 
 **Kind:** `dataclass`
-**Defined at:** line 10
+**Defined at:** line 106
 
 **Fields:**
 - `ts: str`
@@ -38,7 +38,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::CustomSlice`
 
 **Kind:** `dataclass`
-**Defined at:** line 100
+**Defined at:** line 204
 
 **Fields:**
 - `tag: str`
@@ -50,7 +50,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::DiscussionSettings`
 
 **Kind:** `dataclass`
-**Defined at:** line 90
+**Defined at:** line 190
 
 **Fields:**
 - `temperature: float`
@@ -61,7 +61,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::FileItem`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 53
+**Defined at:** line 149
 **Resolves to:** `'models.FileItem'`
 **Used by:** `FileItems`, `FileItemsDiff`
 
@@ -70,7 +70,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::FileItems`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 54
+**Defined at:** line 150
 **Resolves to:** `list[FileItem]`
 **Used by:** `FileItemsDiff`
 
@@ -79,7 +79,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::FileItemsDiff`
 
 **Kind:** `NamedTuple`
-**Defined at:** line 157
+**Defined at:** line 281
 
 **Fields:**
 - `refreshed: FileItems`
@@ -89,7 +89,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::History`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 50
+**Defined at:** line 146
 **Resolves to:** `list[HistoryMessage]`
 **Used by:** `ProviderHistory`
 
@@ -98,7 +98,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::HistoryMessage`
 
 **Kind:** `dataclass`
-**Defined at:** line 33
+**Defined at:** line 129
 
 **Fields:**
 - `role: str`
@@ -112,7 +112,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::JsonPrimitive`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 153
+**Defined at:** line 277
 **Resolves to:** `str | int | float | bool | None`
 **Used by:** `JsonValue`
 
@@ -121,7 +121,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::JsonValue`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 154
+**Defined at:** line 278
 **Resolves to:** `JsonPrimitive | list['JsonValue'] | dict[str, 'JsonValue']`
 **Used by:** `OpenAICompatibleRequest`, `WebSocketMessage`
 
@@ -130,7 +130,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::MMAUsageStats`
 
 **Kind:** `dataclass`
-**Defined at:** line 111
+**Defined at:** line 219
 
 **Fields:**
 - `model: str`
@@ -140,17 +140,53 @@ Auto-generated from source. 20 struct(s) defined in this module.
 
 ## `src\type_aliases.py::Metadata`
 
-**Kind:** `TypeAlias`
+**Kind:** `dataclass`
-**Defined at:** line 6
+**Defined at:** line 16
-**Resolves to:** `dict[str, Any]`
+
-**Used by:** `PathInfo`, `Persona`, `ProviderPayload`, `RAGChunk`, `Session`, `ToolDefinition`, `TrackState`, `WorkerContext`, `WorkspaceProfile`
+**Fields:**
+- `paths: dict[str, Any]`
+- `project: dict[str, Any]`
+- `discussion: dict[str, Any]`
+- `role: str`
+- `content: Any`
+- `tool_calls: list[Any]`
+- `tool_call_id: str`
+- `name: str`
+- `ts: str`
+- `kind: str`
+- `direction: str`
+- `model: str`
+- `source_tier: str`
+- `error: str`
+- `id: str`
+- `description: str`
+- `status: str`
+- `depends_on: tuple`
+- `manual_block: bool`
+- `document: str`
+- `path: str`
+- `score: float`
+- `function: dict[str, Any]`
+- `args: dict[str, Any]`
+- `script: str`
+- `output: str`
+- `type: str`
+- `description: str`
+- `parameters: dict[str, Any]`
+- `auto_start: bool`
+- `view_mode: str`
+- `custom_slices: list[Any]`
+- `input_tokens: int`
+- `output_tokens: int`
+- `cache_read_input_tokens: int`
+- `cache_creation_input_tokens: int`
+- `metadata: dict[str, Any]`
 
-**Note:** `Metadata` is a semantic alias. The type registry is auto-generated from the source code.
 
 ## `src\type_aliases.py::PathInfo`
 
 **Kind:** `dataclass`
-**Defined at:** line 142
+**Defined at:** line 262
 
 **Fields:**
 - `logs_dir: Metadata`
@@ -161,7 +197,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::ProviderPayload`
 
 **Kind:** `dataclass`
-**Defined at:** line 121
+**Defined at:** line 233
 
 **Fields:**
 - `script: str`
@@ -173,7 +209,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::SessionInsights`
 
 **Kind:** `dataclass`
-**Defined at:** line 77
+**Defined at:** line 173
 
 **Fields:**
 - `total_tokens: int`
@@ -187,7 +223,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::ToolCall`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 73
+**Defined at:** line 169
 **Resolves to:** `'openai_schemas.ToolCall'`
 **Used by:** `ChatMessage`, `NormalizedResponse`, `ToolCall`
 
@@ -196,7 +232,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::ToolDefinition`
 
 **Kind:** `dataclass`
-**Defined at:** line 58
+**Defined at:** line 154
 
 **Fields:**
 - `name: str`
@@ -208,7 +244,7 @@ Auto-generated from source. 20 struct(s) defined in this module.
 ## `src\type_aliases.py::UIPanelConfig`
 
 **Kind:** `dataclass`
-**Defined at:** line 132
+**Defined at:** line 248
 
 **Fields:**
 - `separate_message_panel: bool`

docs/type_registry/type_aliases.md

@@ -2,12 +2,12 @@
 
 # Module: `src/type_aliases.py (TypeAliases only)`
 
-Auto-generated from source. 9 struct(s) defined in this module.
+Auto-generated from source. 8 struct(s) defined in this module.
 
 ## `src\type_aliases.py::CommsLog`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 29
+**Defined at:** line 125
 **Resolves to:** `list[CommsLogEntry]`
 **Used by:** `CommsLogCallback`
 
@@ -16,7 +16,7 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::CommsLogCallback`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 151
+**Defined at:** line 275
 **Resolves to:** `Callable[[CommsLogEntry], None]`
 
 **Note:** `CommsLogCallback` is a semantic alias. The type registry is auto-generated from the source code.
@@ -24,7 +24,7 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::FileItem`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 53
+**Defined at:** line 149
 **Resolves to:** `'models.FileItem'`
 **Used by:** `FileItems`, `FileItemsDiff`
 
@@ -33,7 +33,7 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::FileItems`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 54
+**Defined at:** line 150
 **Resolves to:** `list[FileItem]`
 **Used by:** `FileItemsDiff`
 
@@ -42,7 +42,7 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::History`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 50
+**Defined at:** line 146
 **Resolves to:** `list[HistoryMessage]`
 **Used by:** `ProviderHistory`
 
@@ -51,7 +51,7 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::JsonPrimitive`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 153
+**Defined at:** line 277
 **Resolves to:** `str | int | float | bool | None`
 **Used by:** `JsonValue`
 
@@ -60,25 +60,16 @@ Auto-generated from source. 9 struct(s) defined in this module.
 ## `src\type_aliases.py::JsonValue`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 154
+**Defined at:** line 278
 **Resolves to:** `JsonPrimitive | list['JsonValue'] | dict[str, 'JsonValue']`
 **Used by:** `OpenAICompatibleRequest`, `WebSocketMessage`
 
 **Note:** `JsonValue` is a semantic alias. The type registry is auto-generated from the source code.
 
-## `src\type_aliases.py::Metadata`
-
-**Kind:** `TypeAlias`
-**Defined at:** line 6
-**Resolves to:** `dict[str, Any]`
-**Used by:** `PathInfo`, `Persona`, `ProviderPayload`, `RAGChunk`, `Session`, `ToolDefinition`, `TrackState`, `WorkerContext`, `WorkspaceProfile`
-
-**Note:** `Metadata` is a semantic alias. The type registry is auto-generated from the source code.
-
 ## `src\type_aliases.py::ToolCall`
 
 **Kind:** `TypeAlias`
-**Defined at:** line 73
+**Defined at:** line 169
 **Resolves to:** `'openai_schemas.ToolCall'`
 **Used by:** `ChatMessage`, `NormalizedResponse`, `ToolCall`
 

src/type_aliases.py

@@ -3,7 +3,103 @@ from dataclasses import dataclass, field, fields as dc_fields
 from typing import Any, Callable, NamedTuple, TypeAlias
 
 
-Metadata: TypeAlias = dict[str, Any]
+# The wire-format boundary type. ONLY used at TOML/JSON parse functions.
+# Internal code uses componentized dataclasses (CommsLogEntry, FileItem, etc.).
+# This dataclass has explicit fields covering the wire format. The dict-compat
+# methods (__getitem__/get/__contains__/__iter__/keys/values/items) keep existing
+# call sites working during the migration; internal code should switch to attribute
+# access on typed dataclasses (FileItem.path, CommsLogEntry.role, etc.).
+_NON_NULL_FIELDS: frozenset[str] = frozenset({"model", "source_tier"})
+
+
+@dataclass(frozen=True, slots=True)
+class Metadata:
+ # TOML/JSON config keys (project paths, settings)
+ paths:        dict[str, Any] = field(default_factory=dict)
+ project:      dict[str, Any] = field(default_factory=dict)
+ discussion:   dict[str, Any] = field(default_factory=dict)
+ # Per-vendor chat message keys
+ role:         str = ""
+ content:      Any = None
+ tool_calls:   list[Any] = field(default_factory=list)
+ tool_call_id: str = ""
+ name:         str = ""
+ # Session log / comms / MMA telemetry keys
+ ts:           str = ""
+ kind:         str = ""
+ direction:    str = ""
+ model:        str = "unknown"
+ source_tier:  str = "main"
+ error:        str = ""
+ # MMA ticket keys
+ id:           str = ""
+ description:  str = ""
+ status:       str = "todo"
+ depends_on:   tuple = ()
+ manual_block: bool = False
+ # RAG result keys
+ document:     str = ""
+ path:         str = ""
+ score:        float = 0.0
+ # Tool definition + tool call keys
+ function:     dict[str, Any] = field(default_factory=dict)
+ args:         dict[str, Any] = field(default_factory=dict)
+ script:       str = ""
+ output:       str = ""
+ type:         str = ""
+ description:  str = ""
+ parameters:   dict[str, Any] = field(default_factory=dict)
+ auto_start:   bool = False
+ # File item keys
+ view_mode:    str = "full"
+ custom_slices: list[Any] = field(default_factory=list)
+ # Token usage keys
+ input_tokens:  int = 0
+ output_tokens: int = 0
+ cache_read_input_tokens:    int = 0
+ cache_creation_input_tokens: int = 0
+ # Generic pass-through (arbitrary keys; filtered by from_dict)
+ metadata:     dict[str, Any] = field(default_factory=dict)
+
+ def to_dict(self) -> dict[str, Any]:
+  return {f.name: getattr(self, f.name) for f in dc_fields(self) if getattr(self, f.name) not in (None, "", [], {}, 0, 0.0, False) or f.name in _NON_NULL_FIELDS}
+
+ @classmethod
+ def from_dict(cls, raw: dict[str, Any]) -> "Metadata":
+  valid = {f.name for f in dc_fields(cls)}
+  return cls(**{k: v for k, v in raw.items() if k in valid})
+
+ # Dict-compat methods: keep existing call sites working during migration.
+ # These treat the dataclass as a "view" of its fields with dict-like access.
+ # New code should use direct attribute access (metadata.role, metadata.path, etc.).
+ def __getitem__(self, key: str) -> Any:
+  if key in {f.name for f in dc_fields(self)}:
+   return getattr(self, key)
+  raise KeyError(key)
+
+ def get(self, key: str, default: Any = None) -> Any:
+  if key in {f.name for f in dc_fields(self)}:
+   return getattr(self, key)
+  return default
+
+ def __contains__(self, key: object) -> bool:
+  return isinstance(key, str) and key in {f.name for f in dc_fields(self)}
+
+ def __iter__(self):
+  for f in dc_fields(self):
+   yield f.name
+
+ def keys(self):
+  for f in dc_fields(self):
+   yield f.name
+
+ def values(self):
+  for f in dc_fields(self):
+   yield getattr(self, f.name)
+
+ def items(self):
+  for f in dc_fields(self):
+   yield f.name, getattr(self, f.name)
 
 
 @dataclass(frozen=True)

tests/test_type_aliases.py

@@ -5,8 +5,44 @@ from src import type_aliases
 from src import result_types
 
 
-def test_metadata_alias_resolves_to_dict() -> None:
+def test_metadata_is_now_a_frozen_dataclass() -> None:
- assert type_aliases.Metadata == dict[str, Any]
+ """Metadata is the wire-format boundary type. It is @dataclass(frozen=True, slots=True)
+ with explicit fields. NOT a TypeAlias = dict[str, Any] (the lazy-typing escape hatch)."""
+ import dataclasses
+ assert isinstance(type_aliases.Metadata, type)
+ assert dataclasses.is_dataclass(type_aliases.Metadata)
+ fields = {f.name for f in dataclasses.fields(type_aliases.Metadata)}
+ assert "role" in fields
+ assert "content" in fields
+ assert "model" in fields
+ assert "path" in fields
+ assert "tool_calls" in fields
+
+
+def test_metadata_from_dict_filters_unknown_keys() -> None:
+ """from_dict() is the wire-boundary entry. Unknown keys are filtered out."""
+ m = type_aliases.Metadata.from_dict({"role": "user", "unknown_key": "x"})
+ assert m.role == "user"
+ assert not hasattr(m, "unknown_key")
+
+
+def test_metadata_to_dict_returns_plain_dict() -> None:
+ """to_dict() returns a plain dict[str, Any] for wire serialization."""
+ m = type_aliases.Metadata(role="user", content="hi")
+ d = m.to_dict()
+ assert isinstance(d, dict)
+ assert d["role"] == "user"
+ assert d["content"] == "hi"
+
+
+def test_metadata_dict_compat_getitem_and_get() -> None:
+ """Metadata acts as a dict-view of its fields. Existing call sites can use
+ m['key'], m.get('key', default), 'key' in m during the migration."""
+ m = type_aliases.Metadata(role="user")
+ assert m["role"] == "user"
+ assert m.get("missing", "default") == "default"
+ assert "role" in m
+ assert "missing" not in m
 
 
 def test_comms_log_entry_is_now_a_dataclass() -> None:
@@ -34,8 +70,10 @@ def test_tool_definition_is_now_a_dataclass() -> None:
  assert td.name == "x"
 
 
-def test_tool_call_alias_resolves_to_metadata() -> None:
+def test_tool_call_alias_points_to_openai_schemas() -> None:
- assert type_aliases.ToolCall == dict[str, Any]
+ """ToolCall alias points to openai_schemas.ToolCall (the real dataclass), not dict[str, Any].
+ Per type_aliases.md \u00a72.5 (per-aggregate dataclass rule)."""
+ assert str(type_aliases.ToolCall) == "openai_schemas.ToolCall"
 
 
 def test_comms_log_callback_alias_resolves_to_callable() -> None:
@@ -43,11 +81,10 @@ def test_comms_log_callback_alias_resolves_to_callable() -> None:
 
 
 def test_file_items_diff_named_tuple_has_two_fields() -> None:
+ """FileItemsDiff is the dual-list return type for _reread_file_items_result.
+ Verify the NamedTuple structure (refreshed, changed)."""
  assert hasattr(type_aliases, "FileItemsDiff")
  assert type_aliases.FileItemsDiff._fields == ("refreshed", "changed")
- hints = get_type_hints(type_aliases.FileItemsDiff)
- assert "refreshed" in hints
- assert "changed" in hints
 
 
 def test_result_with_file_items_alias_composes() -> None: