feat: MSC4260 Report User, Bug #6 mutual exclusion, TDS toast compliance

- Add ReportUserModal.tsx — category dropdown + reason input, calls
  POST /_matrix/client/v3/users/{userId}/report via mx.http.authedRequest,
  inline success/error feedback, auto-closes 1500ms after success
- Wire Report User button into UserRoomProfile.tsx between UserModeration
  and UserDeviceSessions (hidden for own profile)
- Bug #6: enforce mutual exclusion between chat backgrounds and seasonal
  themes — ChatBgGrid clears seasonal→'off' on non-'none' pick;
  SeasonalBgGrid clears chatBackground→'none' on real theme pick;
  SeasonalEffect guards against legacy persisted state at render time
- TDS: strip all hardcoded hex/rgba fallbacks from LotusToastContainer.tsx
  (var(--lt-bg-card), --lt-accent-orange, --lt-text-primary/secondary,
  --lt-accent-orange-dim/border, --lt-box-glow-orange)
- Mark Bug #6 FIXED, MSC4260 DONE, toast TDS FIXED in LOTUS_BUGS.md and
  LOTUS_TODO.md; note EventReaders + CallControls already compliant

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

LOTUS_BUGS.md

@@ -60,10 +60,10 @@ This document tracks identified bugs, edge cases, and architectural discrepancie
 ### 6. Exclusive Background vs. Seasonal Choice
 
 - **File:** `cinny/src/app/state/settings.ts`
-- **Status:** **OPEN**
+- **Status:** **FIXED**
 - **Issue:** Concurrent application of both Chat Backgrounds and Seasonal Themes causes visual clutter and high GPU usage.
 - **Root Cause:** These are currently handled as independent settings in the `settingsAtom` and applied simultaneously without mutual exclusion.
-- **Proposed Fix:** Introduce mutual exclusion in the settings application logic. Update the settings UI to present these as a single choice (e.g., a radio group or toggled selection) where activating one deactivates the other. Enforce this rule in `cinny/src/app/features/lotus/chatBackground.ts` and `cinny/src/app/components/seasonal/SeasonalEffect.tsx`.
+- **Fix Applied:** Mutual exclusion enforced at two layers: (1) `General.tsx` — ChatBgGrid clears seasonalThemeOverride→'off' when any non-'none' background is picked; SeasonalBgGrid clears chatBackground→'none' when any real seasonal theme is selected. (2) `SeasonalEffect.tsx` — runtime guard returns null if `chatBackground !== 'none'`, protecting against legacy persisted state.
 
 ### 7. Tiny Touch Targets in Composer Toolbar
 
@@ -149,11 +149,11 @@ This document tracks identified bugs, edge cases, and architectural discrepancie
 | Issue Description                                                     | File Path                                                 |
 | :-------------------------------------------------------------------- | :-------------------------------------------------------- |
 | Hardcoded inline style `cursor: 'pointer'`                            | `cinny/src/app/plugins/react-custom-html-parser.tsx`      |
-| Hardcoded color `#00D4FF`, `#FFB300`                                  | `cinny/src/app/components/event-readers/EventReaders.tsx` |
+| Hardcoded color `#00D4FF`, `#FFB300` ✅ **VERIFIED COMPLIANT**        | `cinny/src/app/components/event-readers/EventReaders.tsx` |
 | Hardcoded color `#EE1D52`, `#9146ff`, `#ff4500`, `#cb3837`, `#f48024` | `cinny/src/app/components/url-preview/UrlPreviewCard.tsx` |
 | Massive number of hardcoded `backgroundColor` values                  | `cinny/src/app/features/lotus/chatBackground.ts`          |
-| Hardcoded colors `#00FF88`, `#FF6B00`                                 | `cinny/src/app/features/call/CallControls.tsx`            |
-| Hardcoded fallback hexes in toast colors                              | `cinny/src/app/features/toast/LotusToastContainer.tsx`    |
+| Hardcoded colors `#00FF88`, `#FF6B00` ✅ **VERIFIED COMPLIANT**       | `cinny/src/app/features/call/CallControls.tsx`            |
+| Hardcoded fallback hexes in toast colors ✅ **FIXED**                 | `cinny/src/app/features/toast/LotusToastContainer.tsx`    |
 
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