chore(deps): add Vue Flow and Pinia with pnpm workspace config

pnpm-workspace.yaml opts vue-demi out of build scripts; Vue Flow pulls
it in transitively and pnpm 11 otherwise fails the install on it.

package.json

@@ -13,7 +13,11 @@
     "fmt:check": "oxfmt --check"
   },
   "dependencies": {
+    "@vue-flow/background": "^1.3.2",
+    "@vue-flow/controls": "^1.1.3",
+    "@vue-flow/core": "^1.48.2",
     "daisyui": "^5.5.23",
+    "pinia": "^3.0.4",
     "vue": "^3.5.34"
   },
   "devDependencies": {