fix(security): resolve fast-xml-parser DoS vulnerability (CVE-2026-26278) (#326)

Add pnpm override to force fast-xml-parser >=5.3.6, fixing Dependabot
alert #114 (GHSA-jmr7-xgp7-cmfj, CVSS 7.5). Resolves two vulnerable
transitive instances: 4.5.3 via @loaders.gl/xml and 5.3.4 via
@aws-sdk/xml-builder.

Author: mbarrenechea

client/package.json

@@ -178,6 +178,9 @@
       "sharp",
       "unrs-resolver",
       "es5-ext"
-    ]
+    ],
+    "overrides": {
+      "fast-xml-parser": ">=5.3.6"
+    }
   }
 }