Add flexible listing_type support and last_update_date field

- Add support for str, list[str], and None as listing_type values
  - Single string: maintains backward compatibility (e.g., "for_sale")
  - List of strings: returns properties matching ANY status (OR logic)
  - None: returns all property types (omits status filter)

- Expand ListingType enum with all GraphQL HomeStatus values
  - Add OFF_MARKET, NEW_COMMUNITY, OTHER, READY_TO_BUILD

- Add last_update_date field support
  - Add to GraphQL query, Property model, and processors
  - Add to sort validation and datetime field sorting
  - Field description: "Last time the home was updated"

- Update GraphQL query construction to support status arrays
  - Single type: status: for_sale
  - Multiple types: status: [for_sale, sold]
  - None: omit status parameter entirely

- Update validation logic to handle new parameter types

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

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

homeharvest/core/scrapers/__init__.py

@@ -13,7 +13,7 @@ from pydantic import BaseModel
 
 class ScraperInput(BaseModel):
     location: str
-    listing_type: ListingType
+    listing_type: ListingType | list[ListingType] | None
     property_type: list[SearchPropertyType] | None = None
     radius: float | None = None
     mls_only: bool | None = False