* collection sync with orphan handling
- preview_sync endpoint shows what'll get deleted before you commit
- import services handle reconciliation (find missing items, delete them)
- grid items get flagged as orphaned when their collection source is gone
- party exposes has_orphaned_items
- blueprints include orphaned field
* scope artifact sync by element and proficiency
- accept filter param in preview_sync and import
- only check/delete items matching active filter
- prevents accidental deletion of filtered-out items
* scope weapon sync by element and proficiency
- accept filter param in preview_sync and import
- element checks collection_weapon first, falls back to weapon
- proficiency joins through weapon table
* scope summon sync by element
- accept filter param in preview_sync and import
- element joins through summon table
- preview_sync endpoint shows what'll get deleted before you commit
- import services handle reconciliation (find missing items, delete them)
- grid items get flagged as orphaned when their collection source is gone
- party exposes has_orphaned_items
- blueprints include orphaned field
- Add ArtifactImportService to parse game JSON and create collection artifacts
- Maps game skill_id to our (group, modifier) format using verified mapping
- Handles skill quality -> strength lookup via ArtifactSkill.base_values
- Supports duplicate detection via game_id, with optional update_existing flag
- Quirk artifacts get proficiency from game data; skills stored as empty
- Add POST /collection/artifacts/import endpoint
- Add game_id column to collection_artifacts, collection_weapons,
collection_summons for tracking game inventory instance IDs
