feat: seasonal theme overlays + improved animated chat backgrounds

Adds 11 CSS-only seasonal overlays (Halloween, Christmas, New Year, Autumn,
April Fool's, Lunar New Year, Valentine's Day, St. Patrick's Day, Earth Day,
Deep Space, Retro Arcade) with date-based auto-detection and a manual override
dropdown in Settings → Appearance → Seasonal Theme. All themes respect
prefers-reduced-motion. SeasonalEffect mounts at z-index 9997 in App.tsx.

Also rewrites all 5 animated chat background keyframes for smoother, more
organic motion: Digital Rain gains a phosphor glow flicker; Star Drift now
loops each layer by exactly its own tile size (no more seam); Grid Pulse adds
an independent brightness oscillation at a prime period; Aurora Flow drives
all four gradient layers through distinct paths; Fireflies adds glow-pulse and
opacity-blink animations at prime periods for unsynchronised bioluminescence.

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

LOTUS_TODO.md

@@ -104,17 +104,6 @@ Status: `[ ]` pending · `[~]` in progress · `[x]` completed
 
 ---
 
-## Known Bugs
-
-### [!] BUG · Drag-and-drop file overlay doesn't dismiss on hover-away
-
-**Confirmed bug** — drag a file over the window without dropping: the drop overlay persists.  
-**Fix:** Ensure `dragleave` fires correctly at the window/document level. Child element boundaries can cause spurious `dragleave` — use a counter or `relatedTarget` check.  
-**[AUDIT REQUIRED]** Find the drag-and-drop overlay component in `RoomInput.tsx` or the room view. Confirm the exact event listener structure.  
-**Complexity:** Low (bug fix).
-
----
-
 ## Priority 3 — Higher complexity / lower daily frequency
 
 ### [ ] P3-4 · Accessibility Improvements (WCAG 2.1 AA)
@@ -248,11 +237,9 @@ Themes:
 
 ---
 
-### [ ] P5-9 · LFG (Looking for Group) Slash Command
+### [MOVED] P5-9 · LFG (Looking for Group) Command → LotusBot
 
-**What:** `/lfg` generates a formatted LFG post visible on ALL Matrix clients using standard `m.room.message` HTML. Fields: Game, Players Needed, Platform, Skill Level, Description, DM link. Other clients see clean formatted HTML; Lotus Chat renders an enhanced styled card.  
-**[AUDIT REQUIRED]** Test which HTML tags survive Matrix HTML sanitization on Element/FluffyChat before designing the card structure. Test with minimal HTML.  
-**Complexity:** Medium.
+**Decision:** Implemented as `!lfg` in LotusBot rather than a client slash command. Bot-side rendering works consistently across all Matrix clients; client-side enhanced cards would only be visible to Lotus Chat users and require sanitizer auditing. The bot can also support richer flows (list active LFGs, DM interested players, auto-expire posts).
 
 ---
 
@@ -350,6 +337,32 @@ Themes:
 
 ---
 
+### [ ] P5-30 · Advanced ML Noise Suppression (Krisp-style)
+
+**What:** High-end background noise cancellation using a pre-trained ML model (e.g. RNNoise) running in the browser. Removes dogs, fans, and keyboard clicks from the mic stream.  
+**Note:** This is a top-tier feature request and an EXTREME COMPLEXITY project.  
+**[AUDIT REQUIRED]** Must verify if mixing a processed stream into Element Call's WebRTC implementation causes latency or AEC (Echo Cancellation) issues.  
+**Complexity:** Extreme.
+
+---
+
+### [ ] P5-31 · Granular Voice & Screenshare Quality Controls (Discord-style)
+
+**What:** Let users (or room admins via room settings) adjust audio bitrates (e.g., 64kbps to 512kbps) and screenshare quality (resolution: 720p/1080p/Source, framerate: 15/30/60fps).  
+**Note:** Requires tight integration with the LiveKit SFU and custom state events for per-room quality caps.  
+**[AUDIT REQUIRED]** Must verify if current `lk-jwt-service` can be extended with custom bitrate/resolution claims or if a new sidecar (similar to `voice-limit-guard`) is needed for server-side enforcement.  
+**Complexity:** Extreme.
+
+---
+
+### [ ] P5-34 · User-to-User Private Notes
+
+**What:** A private "Notes" field on user profiles visible only to you. Syncs across all your devices.  
+**Matrix Tech:** Store in `io.lotus.user_notes` account data. Must be keyed by `userId`.  
+**Complexity:** Medium.
+
+---
+
 ## Blocked Features
 
 These features are confirmed desirable but cannot be built until the listed dependency is resolved.