docs: move the LOTUS_TODO / LOTUS_TESTING backlogs into Gitea issues; keep a reference-only LOTUS_REFERENCE.md

LOTUS_TODO.md → LOTUS_REFERENCE.md (design laws, decided deferrals,
server-blocked features, operational reference only). Every open task was
filed: cinny #195–#210, cinny-desktop #15–#18, matrix #8–#10.

LOTUS_TESTING.md keeps the automated-coverage map, the Playwright notes and
the deploy tip; every manual checklist is now a `qa` issue under the
'Manual QA backlog' (cinny #170–#194, #198) and 'Desktop QA backlog'
(cinny-desktop #11–#14, #18) milestones.

Repointed the README, LOTUS_FEATURES, CI and source comments that
referenced LOTUS_TODO.md.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

src/app/features/common-settings/general/RoomQuality.tsx

@@ -41,7 +41,7 @@ type RoomQualityProps = {
 /**
  * [P5-31] Room-admin quality ceiling. Writes `io.lotus.room_quality`; every
  * Lotus client clamps its per-user quality to these caps. Hard enforcement for
- * ALL Matrix clients is a server-side follow-up (see LOTUS_TODO.md P5-31).
+ * ALL Matrix clients is a server-side follow-up (see cinny #174, D2-8).
  */
 export function RoomQuality({ permissions }: RoomQualityProps) {
   const mx = useMatrixClient();