chore: add external deepmerge utility

pnpm-lock.yaml

@@ -251,6 +251,7 @@ importers:
       '@types/luxon': ^3.2.0
       '@typescript-eslint/eslint-plugin': ^5.48.1
       '@typescript-eslint/parser': ^5.48.1
+      deepmerge-ts: ^5.1.0
       eslint: ^8.31.0
       eslint-config-prettier: ^8.6.0
       eslint-plugin-prettier: ^4.2.1
@@ -262,6 +263,7 @@ importers:
       typescript: ^4.9.4
       vitest: ^0.30.1
     dependencies:
+      deepmerge-ts: 5.1.0
       luxon: 3.3.0
       nanoid: 4.0.1
     devDependencies:
@@ -4156,6 +4158,11 @@ packages:
     resolution: {integrity: sha512-oIPzksmTg4/MriiaYGO+okXDT7ztn/w3Eptv/+gSIdMdKsJo0u4CfYNFJPy+4SKMuCqGw2wxnA+URMg3t8a/bQ==}
     dev: true
 
+  /deepmerge-ts/5.1.0:
+    resolution: {integrity: sha512-eS8dRJOckyo9maw9Tu5O5RUi/4inFLrnoLkBe3cPfDMx3WZioXtmOew4TXQaxq7Rhl4xjDtR7c6x8nNTxOvbFw==}
+    engines: {node: '>=16.0.0'}
+    dev: false
+
   /deepmerge/4.3.0:
     resolution: {integrity: sha512-z2wJZXrmeHdvYJp/Ux55wIjqo81G5Bp4c+oELTW+7ar6SogWHajt5a9gO3s3IDaGSAXjDk0vlQKN3rms8ab3og==}
     engines: {node: '>=0.10.0'}