fix(DIDView): validate DID format before processing URL parameters

- Add DID validation using isDid() function to prevent invalid DIDs from loading current user's info
- Show error message and redirect to HomeView for invalid DID formats (e.g., /did/0)
- Import NOTIFY_CONTACT_INVALID_DID constant for consistent error messaging

Resolves: DIDView loading current user's info for invalid DID parameters

src/views/DIDView.vue

@@ -273,6 +273,7 @@ import {
   didInfoForContact,
   displayAmount,
   getHeaders,
+  isDid,
   register,
   setVisibilityUtil,
 } from "../libs/endorserServer";
@@ -289,6 +290,7 @@ import {
   NOTIFY_REGISTRATION_ERROR,
   NOTIFY_SERVER_ACCESS_ERROR,
   NOTIFY_NO_IDENTITY_ERROR,
+  NOTIFY_CONTACT_INVALID_DID,
 } from "@/constants/notifications";
 
 /**
@@ -379,22 +381,29 @@ export default class DIDView extends Vue {
 
   /**
    * Determines which DID to display based on URL parameters
-   * Falls back to active DID if no parameter provided
+   * Validates DID format and shows error for invalid DIDs
    */
   private async determineDIDToDisplay() {
     const pathParam = window.location.pathname.substring("/did/".length);
     let showDid = pathParam;
 
     if (!showDid) {
+      // No DID provided in URL, use active DID
       showDid = this.activeDid;
-      if (showDid) {
-        this.notifyDefaultToActiveDID();
+      this.notifyDefaultToActiveDID();
+    } else {
+      // DID provided in URL, validate it
+      const decodedDid = decodeURIComponent(showDid);
+      if (!isDid(decodedDid)) {
+        // Invalid DID format - show error and redirect
+        this.notify.error(NOTIFY_CONTACT_INVALID_DID.message, TIMEOUTS.LONG);
+        this.$router.push({ name: "home" });
+        return;
       }
+      showDid = decodedDid;
     }
 
-    if (showDid) {
-      this.viewingDid = decodeURIComponent(showDid);
-    }
+    this.viewingDid = showDid;
   }
 
   /**