chore: use preview @electric-sql/client with move-in support

Switch to the preview package from electric-sql/electric#4043 so that
move-in event types are available without unsafe casts in tests.

NOTE: replace the preview URL with the released version before merging.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: kevin-dp

packages/electric-db-collection/package.json

@@ -46,7 +46,7 @@
     "src"
   ],
   "dependencies": {
-    "@electric-sql/client": "^1.5.3",
+    "@electric-sql/client": "https://pkg.pr.new/@electric-sql/client@4043",
     "@standard-schema/spec": "^1.1.0",
     "@tanstack/db": "workspace:*",
     "@tanstack/store": "^0.8.0",

packages/electric-db-collection/tests/tags.test.ts

@@ -1587,7 +1587,7 @@ describe(`Electric Tag Tracking and GC`, () => {
           event: `move-in`,
           patterns: [{ pos: 1, value: `hash_b` }],
         },
-      } as unknown as Message<Row>,
+      },
       {
         headers: { control: `up-to-date` },
       },
@@ -1657,7 +1657,7 @@ describe(`Electric Tag Tracking and GC`, () => {
           event: `move-in`,
           patterns: [{ pos: 0, value: `hash_a` }],
         },
-      } as unknown as Message<Row>,
+      },
       {
         headers: { control: `up-to-date` },
       },
@@ -1725,7 +1725,7 @@ describe(`Electric Tag Tracking and GC`, () => {
           event: `move-in`,
           patterns: [{ pos: 0, value: `hash_a` }],
         },
-      } as unknown as Message<Row>,
+      },
       {
         headers: { control: `up-to-date` },
       },