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/spool.py

@@ -534,6 +534,69 @@ async def delete(
     return Message(message="Success!")
 
 
+# Bulk operations
+
+
+class BulkArchiveParameters(BaseModel):
+    spool_ids: list[int] = Field(description="List of spool IDs to archive/unarchive.")
+    archived: bool = Field(description="Whether to archive (true) or unarchive (false).")
+
+
+class BulkDeleteParameters(BaseModel):
+    spool_ids: list[int] = Field(description="List of spool IDs to delete.")
+
+
+class BulkUpdateParameters(BaseModel):
+    spool_ids: list[int] = Field(description="List of spool IDs to update.")
+    location: Optional[str] = Field(None, max_length=64, description="New location for all spools.")
+
+
+@router.post(
+    "/bulk/archive",
+    name="Bulk archive spools",
+    description="Archive or unarchive multiple spools at once.",
+    responses={404: {"model": Message}},
+)
+async def bulk_archive(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    body: BulkArchiveParameters,
+) -> Message:
+    for spool_id in body.spool_ids:
+        await spool.update(db=db, spool_id=spool_id, data={"archived": body.archived})
+    return Message(message=f"Updated {len(body.spool_ids)} spools.")
+
+
+@router.post(
+    "/bulk/delete",
+    name="Bulk delete spools",
+    description="Delete multiple spools at once.",
+    responses={404: {"model": Message}},
+)
+async def bulk_delete(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    body: BulkDeleteParameters,
+) -> Message:
+    for spool_id in body.spool_ids:
+        await spool.delete(db=db, spool_id=spool_id)
+    return Message(message=f"Deleted {len(body.spool_ids)} spools.")
+
+
+@router.post(
+    "/bulk/update",
+    name="Bulk update spools",
+    description="Update the same fields on multiple spools at once.",
+    responses={404: {"model": Message}},
+)
+async def bulk_update(
+    db: Annotated[AsyncSession, Depends(get_db_session)],
+    body: BulkUpdateParameters,
+) -> Message:
+    data = body.model_dump(exclude={"spool_ids"}, exclude_unset=True)
+    for spool_id in body.spool_ids:
+        await spool.update(db=db, spool_id=spool_id, data=data)
+    return Message(message=f"Updated {len(body.spool_ids)} spools.")
+
+
 @router.put(
     "/{spool_id}/use",
     name="Use spool filament",