fix: add chai as explicit devDependency for legacy-peer-deps compat

chai is a peer dep of chai-as-promised but legacy-peer-deps=true
causes npm to skip auto-installing peer deps. Adding it explicitly
fixes the "Cannot find module 'chai'" error in Linux CI.

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

Author: TimelordUK

package-lock.json

@@ -41,7 +41,6 @@
     "prebuild-install": "^7.1.3"
   },
   "devDependencies": {
-    "env-cmd": "^11.0.0",
     "@types/chai": "^5.2.3",
     "@types/chai-as-promised": "^8.0.2",
     "@types/mocha": "^10.0.10",
@@ -51,10 +50,12 @@
     "@types/sinon": "^21.0.0",
     "@typescript-eslint/eslint-plugin": "^6.21.0",
     "@typescript-eslint/parser": "^6.21.0",
+    "chai": "^4.5.0",
     "chai-as-promised": "^8.0.2",
     "dotenv": "^17.2.3",
     "electron": "^39.2.7",
     "electron-rebuild": "^3.2.9",
+    "env-cmd": "^11.0.0",
     "eslint": "^8.57.1",
     "eslint-config-standard": "^17.1.0",
     "eslint-config-standard-with-typescript": "^43.0.1",