Fix lint errors: remove unused imports

Removed unused imports from:
- packaging/allocation.py
- packaging/grid_array.py
- packaging/port_desc.py
- platforms/_utils.py
- utils.py
- tests/test_init.py

All ruff checks passing.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: robtaylor

chipflow_lib/packaging/allocation.py

@@ -10,14 +10,14 @@
 import logging
 from collections import OrderedDict, deque
 from pprint import pformat
-from typing import Any, Dict, List, Set, Tuple, Optional
+from typing import Any, Dict, List, Tuple, Optional
 
 from amaranth.lib import io
 
 from .. import ChipFlowError
 from ..io.signatures import IO_ANNOTATION_SCHEMA, IOModel
 from .pins import PinList
-from .port_desc import PortDesc, PortMap, Interface
+from .port_desc import PortDesc, PortMap
 from .lockfile import LockFile
 
 logger = logging.getLogger(__name__)

chipflow_lib/packaging/grid_array.py

@@ -13,7 +13,7 @@
 
 from .base import BasePackageDef
 from .pins import PowerPins, JTAGPins, BringupPins
-from .lockfile import Package, LockFile
+from .lockfile import LockFile
 from .allocation import _linear_allocate_components
 
 if TYPE_CHECKING:

chipflow_lib/packaging/port_desc.py

@@ -10,7 +10,6 @@
 from typing import Dict, Generic, List
 
 import pydantic
-from amaranth.lib import io
 
 from ..io.signatures import IOModel
 from .pins import Pin

chipflow_lib/platforms/_utils.py

@@ -1,20 +1,13 @@
-import abc
-import itertools
 import logging
-import pathlib
 import pydantic
 
-from collections import OrderedDict, deque, defaultdict
 from collections.abc import Iterable
 from pprint import pformat
-from typing import Set, List, Dict, Optional, Union, Literal, Tuple, TypeVar
+from typing import Dict, Tuple
 
-from dataclasses import dataclass, asdict
-from enum import IntEnum, StrEnum, auto
-from math import ceil, floor
+from enum import StrEnum, auto
 from typing import (
-    Any, Annotated, NamedTuple, Generic, Self,
-    TYPE_CHECKING
+    Annotated, TYPE_CHECKING
 )
 from typing_extensions import (
     TypedDict, Unpack, NotRequired
@@ -28,26 +21,14 @@
         )
 
 
-from .. import ChipFlowError, _ensure_chipflow_root, _get_cls_by_reference
+from .. import ChipFlowError, _get_cls_by_reference
 from ._annotate import amaranth_annotate
 from ._sky130 import Sky130DriveMode
-from ..config_models import Config, Process, Voltage, VoltageRange
+from ..config_models import Config
 
 # Import packaging functionality from new module
 from ..packaging import (
-    Pin, PinSet, PinList, Pins,
-    PowerType, JTAGWire, PortType,
-    PowerPins, JTAGPins, BringupPins,
-    PortDesc, Interface, Component, PortMap,
-    PackageDef, Package, LockFile,
-    BasePackageDef, LinearAllocPackageDef,
-    BareDiePackageDef, QuadPackageDef,
-    GAPin, GALayout, GAPackageDef,
-    OFPin, OpenframePackageDef,
-    UnableToAllocate,
-    _count_member_pins, _allocate_pins, _linear_allocate_components,
-    _find_contiguous_sequence, _group_consecutive_items,
-    load_pinlock,
+    JTAGWire,
 )
 
 if TYPE_CHECKING:

chipflow_lib/utils.py

@@ -117,7 +117,6 @@ def top_components(config: 'Config') -> Dict[str, 'wiring.Component']:
     Raises:
         ChipFlowError: If component references are invalid or instantiation fails
     """
-    from amaranth.lib import wiring
     from pprint import pformat
 
     component_configs = {}

tests/test_init.py

@@ -132,7 +132,6 @@ def test_parse_config(self, mock_parse_config_file, mock_ensure_chipflow_root):
         self.assertTrue(mock_parse_config_file.called)
         # Accept either string or Path object
         called_path = mock_parse_config_file.call_args[0][0]
-        expected_path = str(mock_ensure_chipflow_root.return_value / "chipflow.toml")
         actual_path = called_path.as_posix() if hasattr(called_path, 'as_posix') else str(called_path)
         self.assertIn("chipflow.toml", actual_path)
         self.assertEqual(config.chipflow.project_name, "test")