feat: Add batch operations, dashboard redesign, hierarchical locations

## Batch Operations (#13)
- Add POST /spool/bulk/archive, /bulk/delete, /bulk/update endpoints
- Add row selection with checkboxes to spool list
- Add floating BatchActionBar with archive/unarchive/delete/move actions
- Add confirmation modals for all batch operations

## Dashboard Redesign (#12)
- Install recharts for pie charts
- Add AlertCards (low stock, pending jobs, needs weighing)
- Add MaterialDistributionChart (pie chart by material)
- Add QuickStats row (total spools, filaments, vendors, weight)
- Refactor home page layout with new components

## Hierarchical Locations (#9)
- Add Location model with self-referential parent relationship
- Add migration for location table and spool.location_id FK
- Add location database operations (CRUD, tree, full path)
- Add location API endpoints (list, tree, CRUD)
- Add LocationTreeSelect component with nested tree display
- Add LocationCreateModal for inline location creation
- Keep legacy location string field for backward compatibility

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

spoolman/api/v1/location.py

@@ -0,0 +1,164 @@
+"""Location related endpoints."""
+
+from typing import Annotated, Optional
+
+from fastapi import APIRouter, Depends
+from pydantic import BaseModel, Field
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from spoolman.api.v1.models import Message
+from spoolman.database import location
+from spoolman.database.database import get_db_session
+from spoolman.database import models
+
+router = APIRouter(
+    prefix="/location",
+    tags=["location"],
+)
+
+
+class LocationResponse(BaseModel):
+    """Location response model."""
+
+    id: int
+    name: str
+    parent_id: Optional[int] = None
+    location_type: Optional[str] = None
+    description: Optional[str] = None
+    full_path: Optional[str] = None  # Only populated for single-item requests
+    spool_count: Optional[int] = None  # Only populated when requested
+
+    @staticmethod
+    def from_db(item: models.Location, full_path: Optional[str] = None) -> "LocationResponse":
+        return LocationResponse(
+            id=item.id,
+            name=item.name,
+            parent_id=item.parent_id,
+            location_type=item.location_type,
+            description=item.description,
+            full_path=full_path,
+        )
+
+
+class LocationTreeNode(BaseModel):
+    """Location tree node for nested structure."""
+
+    id: int
+    name: str
+    location_type: Optional[str] = None
+    description: Optional[str] = None
+    children: list["LocationTreeNode"] = []
+
+
+class LocationParameters(BaseModel):
+    """Parameters for creating a location."""
+
+    name: str = Field(max_length=64, description="Location name.")
+    parent_id: Optional[int] = Field(None, description="Parent location ID.")
+    location_type: Optional[str] = Field(None, max_length=32, description="Type: room, shelf, bin, etc.")
+    description: Optional[str] = Field(None, max_length=256, description="Optional description.")
+
+
+class LocationUpdateParameters(BaseModel):
+    """Parameters for updating a location."""
+
+    name: Optional[str] = Field(None, max_length=64, description="Location name.")
+    parent_id: Optional[int] = Field(None, description="Parent location ID.")
+    location_type: Optional[str] = Field(None, max_length=32, description="Type: room, shelf, bin, etc.")
+    description: Optional[str] = Field(None, max_length=256, description="Optional description.")
+
+
+@router.get(
+    "",
+    name="Find locations",
+    description="Get all locations as a flat list.",
+    response_model=list[LocationResponse],
+)
+async def find_locations(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> list[LocationResponse]:
+    db_items = await location.find_all(db=db)
+    return [LocationResponse.from_db(item) for item in db_items]
+
+
+@router.get(
+    "/tree",
+    name="Get location tree",
+    description="Get all locations as a nested tree structure.",
+    response_model=list[LocationTreeNode],
+)
+async def get_location_tree(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+) -> list[dict]:
+    return await location.get_tree(db=db)
+
+
+@router.get(
+    "/{location_id}",
+    name="Get location",
+    description="Get a specific location by ID.",
+    response_model=LocationResponse,
+    responses={404: {"model": Message}},
+)
+async def get_location(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    location_id: int,
+) -> LocationResponse:
+    db_item = await location.get_by_id(db=db, location_id=location_id)
+    full_path = await location.get_full_path(db=db, location_id=location_id)
+    spool_count = await location.get_spool_count(db=db, location_id=location_id)
+    response = LocationResponse.from_db(db_item, full_path=full_path)
+    response.spool_count = spool_count
+    return response
+
+
+@router.post(
+    "",
+    name="Create location",
+    description="Create a new location.",
+    response_model=LocationResponse,
+    responses={400: {"model": Message}, 404: {"model": Message}},
+)
+async def create_location(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    body: LocationParameters,
+) -> LocationResponse:
+    db_item = await location.create(
+        db=db,
+        name=body.name,
+        parent_id=body.parent_id,
+        location_type=body.location_type,
+        description=body.description,
+    )
+    return LocationResponse.from_db(db_item)
+
+
+@router.patch(
+    "/{location_id}",
+    name="Update location",
+    description="Update a location.",
+    response_model=LocationResponse,
+    responses={400: {"model": Message}, 404: {"model": Message}},
+)
+async def update_location(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    location_id: int,
+    body: LocationUpdateParameters,
+) -> LocationResponse:
+    data = body.model_dump(exclude_unset=True)
+    db_item = await location.update(db=db, location_id=location_id, data=data)
+    return LocationResponse.from_db(db_item)
+
+
+@router.delete(
+    "/{location_id}",
+    name="Delete location",
+    description="Delete a location. Spools using this location will have their location_id set to null.",
+    responses={404: {"model": Message}},
+)
+async def delete_location(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    location_id: int,
+) -> Message:
+    await location.delete(db=db, location_id=location_id)
+    return Message(message="Success!")