Preserve community data on onboarding write failure

Co-authored-by: npub1cl47vfhsqpqy9pwndphpm36vcp7vvz5h2js4qpqm5yewzj7nutkq7xyw8c <c7ebe626f000404285d3686e1dc74cc07cc60a9754a150041ba132e14bd3e2ec@buzz.block.builderlab.xyz>
Signed-off-by: npub1cl47vfhsqpqy9pwndphpm36vcp7vvz5h2js4qpqm5yewzj7nutkq7xyw8c <c7ebe626f000404285d3686e1dc74cc07cc60a9754a150041ba132e14bd3e2ec@buzz.block.builderlab.xyz>

desktop/src/features/communities/communityStorage.test.mjs

@@ -3,6 +3,7 @@ import test from "node:test";
 
 import {
   clearCommunityStorage,
+  initFirstCommunity,
   migrateLegacyCommunityStorage,
   shouldAutoConnectDefaultRelay,
 } from "./communityStorage.ts";
@@ -10,6 +11,7 @@ import {
 function createMemoryStorage(initial = {}) {
   const values = new Map(Object.entries(initial));
   return {
+    values,
     getItem: (key) => values.get(key) ?? null,
     setItem: (key, value) => values.set(key, String(value)),
     removeItem: (key) => values.delete(key),
@@ -59,6 +61,28 @@ test("signed-build relay defaults auto-connect during first-run onboarding", ()
   assert.equal(shouldAutoConnectDefaultRelay("not a valid relay"), false);
 });
 
+test("failed first-community write preserves existing community data", () => {
+  const storage = createMemoryStorage({
+    "buzz-communities": '[{"id":"existing"}]',
+    "buzz-workspaces": '[{"id":"legacy"}]',
+    "buzz-active-workspace-id": "legacy",
+  });
+  storage.setItem = (key, value) => {
+    if (key === "buzz-communities") {
+      throw new Error("QuotaExceededError");
+    }
+    storage.values.set(key, String(value));
+  };
+  globalThis.localStorage = storage;
+  globalThis.window = { localStorage: storage };
+
+  assert.equal(initFirstCommunity("wss://relay.example.com", "pubkey"), null);
+  assert.equal(storage.getItem("buzz-communities"), '[{"id":"existing"}]');
+  assert.equal(storage.getItem("buzz-active-community-id"), null);
+  assert.equal(storage.getItem("buzz-workspaces"), '[{"id":"legacy"}]');
+  assert.equal(storage.getItem("buzz-active-workspace-id"), "legacy");
+});
+
 test("clearCommunityStorage removes new and legacy state", () => {
   const storage = createMemoryStorage({
     "buzz-communities": "new",

desktop/src/features/communities/communityStorage.ts

@@ -160,14 +160,26 @@ export function initFirstCommunity(
     pubkey,
     addedAt: new Date().toISOString(),
   };
-  const didSaveCommunities = saveCommunities([community]);
-  const didSaveActiveCommunity =
-    didSaveCommunities && saveActiveCommunityId(community.id);
+  const previousActiveCommunityId = localStorage.getItem(ACTIVE_COMMUNITY_KEY);
+  const didSaveActiveCommunity = saveActiveCommunityId(community.id);
+  if (!didSaveActiveCommunity) {
+    return null;
+  }
 
-  // The quota-recovery helper reports failure instead of throwing. Do not let
-  // callers reload unless both writes landed; otherwise first launch can loop.
-  if (!didSaveCommunities || !didSaveActiveCommunity) {
-    clearCommunityStorage();
+  if (!saveCommunities([community])) {
+    // A failed setItem leaves the existing communities value untouched. Roll
+    // back only the active-ID write so inconsistent pre-existing data is never
+    // destroyed while recovering from a quota failure.
+    try {
+      if (previousActiveCommunityId === null) {
+        localStorage.removeItem(ACTIVE_COMMUNITY_KEY);
+      } else {
+        localStorage.setItem(ACTIVE_COMMUNITY_KEY, previousActiveCommunityId);
+      }
+    } catch {
+      // Best effort: persistence is already unavailable, and callers will stay
+      // on setup instead of reloading.
+    }
     return null;
   }