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

LOTUS_FEATURES.md

@@ -332,7 +332,7 @@ Users can set a custom background color for `@mention` chips that highlight thei
 > pre-built npm bundle. Several in-call behaviors below are now first-class
 > source changes rather than DOM/widget hacks. Background, plan, and the Phase-2
 > work list are in
-> the Element Call fork reference in [`LOTUS_TODO.md`](./LOTUS_TODO.md).
+> the Element Call fork reference in [`LOTUS_REFERENCE.md`](./LOTUS_REFERENCE.md).
 
 ### Element Call — Self-Built Fork (`0.20.1-lotus.1`)
 
@@ -1417,7 +1417,7 @@ The session persists as ONE atomic `cinny_session_v1` JSON write (previously ~10
 
 ### Crypto Diagnostics (E2EE investigation kit)
 
-**Settings → Developer Tools → Crypto Diagnostics**: a capture-only ring buffer (max 200) hooks `console.warn/error` for E2EE failure signatures (OTK upload conflicts, missing call media keys, decryption errors, delayed-event timeouts) and downloads a JSON report — the evidence input for the KE-1→4 investigation. Companion diagnosis: the Encryption / E2EE section of [`LOTUS_TODO.md`](./LOTUS_TODO.md). `utils/cryptoDiagLog.ts`, `features/settings/developer/CryptoDiagnostics.tsx`.
+**Settings → Developer Tools → Crypto Diagnostics**: a capture-only ring buffer (max 200) hooks `console.warn/error` for E2EE failure signatures (OTK upload conflicts, missing call media keys, decryption errors, delayed-event timeouts) and downloads a JSON report — the evidence input for the KE-1→4 investigation. Companion diagnosis: the Encryption / E2EE section of [`LOTUS_REFERENCE.md`](./LOTUS_REFERENCE.md). `utils/cryptoDiagLog.ts`, `features/settings/developer/CryptoDiagnostics.tsx`.
 
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