feat(cards): Refactor card styling and implement JS multiselect

Refactors card styling by moving color data to the `CardSet` model, removing the `Card.style` and `Pack.hex_color` fields.

- Adds `hex_color` to `CardSet` and a `CardSetColorMapping` model to populate it during import.
- Card importer now uses correct filename regexes to identify sets and apply color mappings.
- Card badge styling is now derived from the `CardSet`'s color, simplifying the data model.

Replaces the old clunky card multiselect with a dynamic Alpine.js component for an improved user experience.

- Introduces an API endpoint (`cards/api/search/`) for asynchronous searching.
- Provides a modern search-as-you-type interface with a `<noscript>` fallback.

seed/0003_CardSetColorMappings.json

@@ -0,0 +1,79 @@
+[
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 1,
+      "fields": {
+          "cardset_id": "A3a",
+          "hex_color": "#FA1A1A",
+          "created_at": "2025-06-20T05:48:33.579Z",
+          "updated_at": "2025-06-20T06:07:05.636Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 2,
+      "fields": {
+          "cardset_id": "A3",
+          "hex_color": "#0B47C6",
+          "created_at": "2025-06-20T05:49:48.100Z",
+          "updated_at": "2025-06-20T06:06:37.342Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 3,
+      "fields": {
+          "cardset_id": "A2b",
+          "hex_color": "#B3D6EE",
+          "created_at": "2025-06-20T05:57:08.639Z",
+          "updated_at": "2025-06-20T06:06:19.207Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 4,
+      "fields": {
+          "cardset_id": "A2a",
+          "hex_color": "#EA9706",
+          "created_at": "2025-06-20T05:58:45.284Z",
+          "updated_at": "2025-06-20T06:05:40.057Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 5,
+      "fields": {
+          "cardset_id": "A2",
+          "hex_color": "#7A8696",
+          "created_at": "2025-06-20T05:59:26.177Z",
+          "updated_at": "2025-06-20T06:05:23.890Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 6,
+      "fields": {
+          "cardset_id": "A1a",
+          "hex_color": "#31DDAA",
+          "created_at": "2025-06-20T06:01:35.316Z",
+          "updated_at": "2025-06-20T06:05:06.221Z",
+          "deleted_at": null
+      }
+  },
+  {
+      "model": "cards.cardsetcolormapping",
+      "pk": 7,
+      "fields": {
+          "cardset_id": "A1",
+          "hex_color": "#7911F0",
+          "created_at": "2025-06-20T06:03:51.759Z",
+          "updated_at": "2025-06-20T06:04:48.969Z",
+          "deleted_at": null
+      }
+  }
+]