Only show 'edit' on published pages when viewer is the owner. Shared

pages don't grant edit permissions, so this is good enough.  All actual
security is enforced in the API, so this just displays (or not) the
UI.

client/src/components/PageDisplay/PageDisplay.vue

@@ -9,6 +9,7 @@
                         :enable_beta_markdown_export="config.enable_beta_markdown_export"
                         :download-endpoint="stsUrl(config)"
                         :export-link="exportUrl"
+                        :read-only="!userOwnsPage"
                         @onEdit="onEdit" />
                     <PageHtml v-else :page="page" />
                 </div>
@@ -25,6 +26,8 @@ import ConfigProvider from "components/providers/ConfigProvider";
 import Markdown from "components/Markdown/Markdown";
 import Published from "components/Common/Published";
 import PageHtml from "./PageHtml";
+import { mapState } from "pinia";
+import { useUserStore } from "@/stores/userStore";
 
 export default {
     components: {
@@ -45,6 +48,10 @@ export default {
         };
     },
     computed: {
+        ...mapState(useUserStore, ["currentUser"]),
+        userOwnsPage() {
+            return this.currentUser.username === this.page.username;
+        },
         dataUrl() {
             return `/api/pages/${this.pageId}`;
         },