Implemented a Zustand-based project_id store, expanded project selection/switching to persist project_id,

and centralized backend requests via api/apiFetch (including data provider updates) to inject X-Project-ID.

package-lock.json

@@ -41,7 +41,8 @@
         "react-draggable": "^4.5.0",
         "react-icons": "^5.5.0",
         "react-window": "^1.8.10",
-        "tailwindcss": "^4.1.13"
+        "tailwindcss": "^4.1.13",
+        "zustand": "^5.0.11"
       },
       "devDependencies": {
         "@svgr/webpack": "^8.1.0",
@@ -22904,6 +22905,35 @@
       "integrity": "sha512-w2NTI8+3l3eeltKAdK8QpiLo/flRAr2p8AGeakfMZOXBxOg9HIu4LVDxBi81sYgVhFhdJjv1OrB5ssI8uFPoLg==",
       "license": "MIT AND BSD-3-Clause"
     },
+    "node_modules/zustand": {
+      "version": "5.0.11",
+      "resolved": "https://registry.npmjs.org/zustand/-/zustand-5.0.11.tgz",
+      "integrity": "sha512-fdZY+dk7zn/vbWNCYmzZULHRrss0jx5pPFiOuMZ/5HJN6Yv3u+1Wswy/4MpZEkEGhtNH+pwxZB8OKgUBPzYAGg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=12.20.0"
+      },
+      "peerDependencies": {
+        "@types/react": ">=18.0.0",
+        "immer": ">=9.0.6",
+        "react": ">=18.0.0",
+        "use-sync-external-store": ">=1.2.0"
+      },
+      "peerDependenciesMeta": {
+        "@types/react": {
+          "optional": true
+        },
+        "immer": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "use-sync-external-store": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/zwitch": {
       "version": "1.0.5",
       "resolved": "https://registry.npmjs.org/zwitch/-/zwitch-1.0.5.tgz",