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## Summary Mobile does background work nobody sees, and it waits on round trips it doesn't need. This PR fixes four things: - **Chats you've left let go.** A chat with no listener for 30 s drops its live and typing subscriptions. Coming back shows the cached timeline right away, then resubscribes and catches up. - **No requests before AUTH.** The relay rejects any REQ that arrives before NIP-42 AUTH completes. History requests are now held until the socket authenticates, and they flush after the rate-limit gate. Live subscriptions skip their REQ, and the replay on connect sends it. `auth-required` is terminal for a live subscription, so a pre-AUTH live REQ could be dropped for good. - **Resume reconciles the channel list once.** `resumed` is published before the session hears about it. So the channel list now decides one microtask later: if the session is reconnecting, the connect does the reconcile. - **The 60 s backstop only runs in the foreground on a connected session.** After an OS suspension, the missed tick fires at unfreeze, about 450 ms before the app hears `resumed`, while the session still looks connected. Without this, that tick triggered a second full sync. Scope note: while the app is in the foreground, the backstop still re-downloads membership every 60 s. That matches desktop, which refetches every 60 s while focused. To drop it, mobile would need to subscribe to the live membership notices (44100/44101), as desktop does. That would be a follow-up. ### Related issue N/A. This is follow-up work from the mobile perf dive. None found. ## Before and after Simulator setup: iPhone 18 Pro simulator, debug build, a local relay behind a proxy that adds ~120 ms RTT, and a seeded account with 120 channels. I scripted one identical run against each build: 1. Open 5 channels. 2. Visit 20 more channels. 3. Wait 40 s. 4. Stay idle in the foreground for 3 min. 5. Go to the background for 3 min. 6. Resume. `main` is `ca3be5501`; the branch is `d77c4e86f`. The last amend changed only test names. Since then, chat history waits for the live EOSE again (see the note below), so channel open is back to `main`'s order. | | `main` | this PR | |---|---|---| | Live subscriptions after visiting 20 chats | 61 | 11 | | Resume: membership reads | 2 (244 kB) | 1 (122 kB) | | Resume: websocket REQs | 36 | 31 | | Resume: REQs sent before AUTH | 9 | 0 | | Resume: REQs rejected as `auth-required` | 2 | 0 | | Idle foreground, 3 min | 3 membership reads, 12 REQs | same | Notes: - **Channel open:** an earlier revision requested history without waiting for EOSE, which cut the median open from 297 ms to 197 ms. Review showed it can lose a message. The relay registers the live REQ only after its access checks, so a message committed in between reached neither the window read nor the subscription. A timestamp overlap only covers messages signed within it. Keeping that speedup safely would mean a second window read on every open, so it's left out. - **Idle foreground is unchanged by design.** See the scope note above. - **Background traffic:** the simulator suspends the app shortly after it leaves the foreground, so both builds sent almost nothing during the 3 minutes in the background. The backstop fix shows up at unfreeze instead, as the missing second membership read. - **Resume inbound events:** in this one run, events received over the websocket on resume were 247 kB on `main` and 338 kB on the branch. I haven't attributed the difference. ## Test These extend the existing journeys, plus one new journey: - **`channel_messages_journey_test`:** - The window read waits for the live REQ's admission, and a message signed a minute earlier but committed before admission shows up. - After the listener leaves, the chat keeps following for 29 s and stops at 31 s. - Coming back shows the cached rows immediately, then catches up on a message sent while away. - **`relay_session_test`:** a stale-connected resume sends nothing before AUTH. Then exactly one history REQ and one live REQ go out after AUTH. - **New `channels_sync_journey_test`:** drives the real lifecycle, session and channel notifier against `FakeRelay`: - A backgrounding just before a backstop tick sends nothing. - A resume after the session paused syncs once. - An OS-suspension resume with AUTH held syncs once, after AUTH, and sends no REQ before it. - **`FakeRelay`:** gained `holdReq`, `holdAuth`, `before_id` pagination and an injectable clock. Each guard was mutation-checked, and every mutation failed its test: - live REQ sent before AUTH - history sent before AUTH - resume refresh not deferred - backstop without the lifecycle check - history read alongside the live REQ - a 30-day detach delay Follow-up, not in this PR: a history REQ already in flight on a socket that gets replaced still waits for its 8 s timeout. Princess Donut found this in review; it predates this change. ## Validation - `flutter analyze`: clean - Full mobile suite at `678617b`: 3,696 passed - Court review (Princess Donut on the relay session, Mongo on chat subscriptions, Mordecai on the channel list plus a challenge pass): no blocking findings. The rate-limit flush ordering came from that review. **Human test:** Wes ran `da5077d` on the simulator with his real account and confirmed it works. `460dc35` then fixed a review blocker: a chat rebuilt while detached stayed detached. A retest of that path is pending: leave a chat for more than 30 s, background the app for more than 5 s, resume, then reopen the chat. 🤖 Generated with [Claude Code](https://claude.com/claude-code) --------- Signed-off-by: Wes <wesbillman@users.noreply.github.com> Co-authored-by: Carl <32a2e2c9d428ee08902cab75d956da2c1d235a22d4766b0dd4138bf6e2e5db1d@buzz.block.builderlab.xyz> Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>