fix: resume private share bundles after sign-in (Closes #1004)

frontend/login.js

@@ -4,7 +4,7 @@
 }(typeof self !== 'undefined' ? self : this, function createLoginController(options) {
   function validShareContinuation(value) {
     if (typeof value !== 'string' || !value.startsWith('./?') || value.includes('#')) return './';
-    const limits = { title: 200, text: 8000, url: 2048, launch: 8, shared: 5, search: 200,
+    const limits = { title: 200, text: 8000, url: 2048, launch: 8, shared: 6, search: 200,
       preview: 200, search_kind: 5, search_state: 6, search_repository: 161 };
     const params = new URLSearchParams(value.slice(3));
     const entries = Array.from(params.entries());
@@ -35,7 +35,9 @@
     const launch = params.get('launch');
     const shared = params.get('shared');
     if (launch && !['continue', 'new', 'agenda'].includes(launch)) return './';
-    if (shared !== null && (shared !== 'image' || launch !== 'new')) return './';
+    if (shared === 'bundle') {
+      if (launch !== 'new' || entries.some(([name]) => !['launch', 'shared'].includes(name))) return './';
+    } else if (shared !== null && (shared !== 'image' || launch !== 'new')) return './';
     return value;
   }