docs: add DP1-DP18 test items (LOTUS_TESTING §R), retire DP backlog

The discovery-pass items DP1-DP18 are implemented + TPVR-reviewed, so move their
manual QA steps into LOTUS_TESTING.md (new section R) and replace the DP backlog
block in LOTUS_TODO.md with a done-breadcrumb pointing at §R + the commits.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

LOTUS_TESTING.md

@@ -699,6 +699,40 @@ Paste each of these into a room and confirm a media tile (not a plain link) with
 
 ---
 
+## R. Discovery-pass fixes (DP1–DP18, 2026-07)
+
+Agent-surveyed + TPVR-verified low/med issues, now fixed (commits `8eb961b6` `db864326` `6cf18c3b` `165714e1` `8c0e2b42` `e545706c` `b1ee3ada` `4fc3f7a3` `101e4116` `4fa4327a` `c2598d21`). Behavioral items have concrete checks; the refactors just need a "still works" regression pass.
+
+### Correctness
+
+- [ ] **DP1 — slash-command errors are visible.** Run a slash command that must fail — e.g. `/kick @nobody:server` in a room where you lack permission, or `/join` a bad alias. **Expected:** an error toast appears (not a silent no-op); a successful command still clears the composer normally.
+- [ ] **DP2 — no invite re-notify on reload.** With ≥1 pending invite, hard-reload (Ctrl+F5). **Expected:** NO "you have N new invitation" toast/sound on load. Then have someone invite you while the app is open → you DO get one notification for the new invite. (👥 2 accounts)
+- [ ] **DP3 — status clear syncs across devices.** Set a status message on device A, confirm it shows on B; clear it on A. **Expected:** B clears too and does NOT re-publish the old status on its next presence heartbeat. Toggling Invisible must not wipe a real saved status. (👥 2 sessions)
+- [ ] **DP4 — tag-toggle failure surfaced once.** With the network offline, toggle a room's Favourite/Low-priority. **Expected:** a single error toast (not two) on failure; on success the tag updates as before.
+- [ ] **DP5 — soundboard packs update on room switch.** Open a soundboard in room A, then switch to room B (different pack) in the same mounted view. **Expected:** B's packs show without needing an unrelated event.
+- [ ] **DP6 — declining a call still dismisses.** Decline an incoming call. **Expected:** the ringing UI dismisses even if the decline send fails (best-effort). (👥 2 accounts)
+
+### a11y / UX (needs a screen reader + a narrow viewport)
+
+- [ ] **DP7 / DP8 — call-control buttons announce correctly.** In a call with a screen reader: the deafen button announces "Deafen" when sound is on (not "Undeafen"); Sound / Video / Screenshare announce a consistent pressed/unpressed state like Mic.
+- [ ] **DP9 — GIF picker focus + width.** Open the GIF picker, close it (Esc / click-out) → focus returns to the GIF button. On a ~320px viewport the picker doesn't overflow the page.
+- [ ] **DP10 — search-filter clears by keyboard.** In message search, toggle a filter chip (Has link / msg-type / pinned) off with Enter; the date-range clears via its menu's Clear. No mouse-only clear needed.
+- [ ] **DP11 — voice recorder fits + announces.** On a ~360px viewport, start a voice message → the recorder row doesn't overflow the composer; a screen reader can query the duration (role="timer") without being spammed.
+- [ ] **DP12 — live-call count announced.** With a screen reader, when someone joins/leaves an active call, the "{n} Live" change is announced (polite status region).
+
+### TDS colors (Lotus Terminal theme)
+
+- [ ] **DP14 — send-status + receipt colors follow the theme.** In **TDS light** mode: the message send-status "failed" icon and the read-receipt pill use the theme's darker red/blue (from `--lt-*` tokens), NOT bright dark-mode cyan/red. TDS dark still looks right; non-TDS themes unchanged.
+
+### Refactor regression pass (no behavior change intended)
+
+- [ ] **DP13 — bookmarks / reminders / notes still work** (they now share one store engine). Add/remove a bookmark, set/clear a reminder, write/clear a user note; each persists across reload; rapid consecutive writes don't clobber each other.
+- [ ] **DP15 / DP16 — state-event + account-data writes still work.** Edit room name/topic/avatar, join-rules, power levels, an emoji/soundboard pack (state events); toggle a setting stored in account data. All save + reflect correctly.
+- [ ] **DP17 — link previews render.** Open a TikTok / Spotify / Steam / Reddit link preview; provider icons render (folds icons, not raw glyphs) and brand colors look right.
+- [ ] **DP18 — member avatars/names live-update.** Read receipts + the "seen by" reader list show correct avatars/names and update live when a member changes their avatar or display name (no reload).
+
+---
+
 ## Priority if you're short on time
 
 1. **O1 + O2** (threads + per-thread notifications) — the largest new surface; the main-timeline change is user-visible.