landing: structured feature groups, single-source comparison table (#11)

- The ~1,800-word fork paragraph becomes 7 titled groups, one short line
  per feature, plus a link to LOTUS_FEATURES.md.
- Single source: landing/data/features.json + comparison.json, rendered
  into index.html by landing/build.py between BEGIN/END markers (all 71
  table rows re-render with identical cell text).
- CSS moved to landing/style.css; build.py inlines it because the LXC 139
  deploy copies index.html only.
- "Client comparison last reviewed" stamp driven by comparison.json.
- CI job `landing-fresh` fails if index.html drifts from its sources.
- Feature list brought up to date: 629 avatar decorations in 28
  categories, mic level meter + remembered per-person volume, search
  operators, paste-as-code, thread "Mark all read", pinch-zoom/swipe media
  viewer, room widgets with a permission prompt.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA

landing/data/features.json

@@ -0,0 +1,76 @@
+[
+  {
+    "title": "Calls & Voice",
+    "items": [
+      "Voice rooms with our own Element Call fork on a self-hosted LiveKit SFU",
+      "Push-to-talk and push-to-deafen, with system-wide hotkeys on the Windows app (work while a game has focus)",
+      "Mic level meter on the mute button; per-person call volume that's remembered between calls",
+      "On-device noise suppression: Off, browser-native, or ML (RNNoise, Speex, DTLN, DeepFilterNet 3)",
+      "In-call soundboard with your own clips, synced across your devices",
+      "Incoming-call ring with Answer/Decline, join/leave sounds, draggable picture-in-picture window",
+      "Screenshare fullscreen and audio mute; per-user mic/screenshare bitrate and framerate caps",
+      "Server-enforced room limits and permissions (max participants, audio-only, no screenshare) for every Matrix client",
+      "AFK auto-mute after a configurable idle time"
+    ]
+  },
+  {
+    "title": "Messaging",
+    "items": [
+      "Threads with a side panel, unread chips, “Mark all read” and per-thread notification overrides",
+      "Search operators: <code>from:</code>, <code>in:</code>, <code>before:</code>/<code>after:</code> (dates or <code>7d</code>), <code>has:link|image|video|file</code>, <code>is:pinned</code>",
+      "Voice messages with 0.75&times;&ndash;2&times; playback (MSC3245, E2EE)",
+      "Polls, message scheduling (MSC4140), forwarding, captions and location sharing",
+      "Pinned messages, saved messages/bookmarks and private notes on people, synced across devices",
+      "Who-reacted viewer, read receipt avatars, quick reactions on hover",
+      "GIF picker (Giphy), custom emoji &amp; sticker packs, math/LaTeX (KaTeX)",
+      "Pasted code is offered as a formatted code block, with the language detected",
+      "On-device message translation: text never leaves your machine, works in encrypted rooms"
+    ]
+  },
+  {
+    "title": "Media &amp; Links",
+    "items": [
+      "Click-to-play inline embeds: YouTube, Vimeo, Twitch, TikTok, X, Instagram, Reddit, Bluesky, Spotify, SoundCloud, Apple Music, Tidal and more",
+      "Rich link cards for GitHub, Steam, Wikipedia, IMDb, npm and others; animated GIF previews",
+      "Full-screen viewer with pinch-zoom, swipe/arrow-key navigation and captions; media gallery for every file shared in a room",
+      "Optional image compression, folder drag-and-drop upload"
+    ]
+  },
+  {
+    "title": "Privacy &amp; Security",
+    "items": [
+      "Private read receipts, hide typing, hide online status",
+      "Tracking-parameter stripping (utm_*, fbclid, YouTube si= and ~40 more), on your device",
+      "Opt-in on-device search index for encrypted rooms, wiped on logout",
+      "Device verification fixes (cross-client emoji SAS) and a per-member session panel"
+    ]
+  },
+  {
+    "title": "Look &amp; Feel",
+    "items": [
+      "Lotus Terminal theme, night-light filter, glassmorphism sidebar",
+      "Animated chat backgrounds and 11 seasonal overlays (all respect reduced motion)",
+      "629 animated avatar decorations in 28 categories, visible to other Lotus users (MSC4133)",
+      "Custom status with emoji and auto-clear, Discord-style presence rings",
+      "Settings sync across devices (theme, layout, notification and privacy preferences)"
+    ]
+  },
+  {
+    "title": "Desktop App",
+    "items": [
+      "Windows, macOS and Linux (Tauri)",
+      "Rich Windows notifications with inline reply; Focus Assist sync",
+      "Taskbar call controls, jump list and upload progress; tray with call status",
+      "Stays awake during calls, reconnects on network changes, updates itself"
+    ]
+  },
+  {
+    "title": "Rooms &amp; Moderation",
+    "items": [
+      "Knock-to-join with an admin approve/deny panel and live pending-count badge",
+      "Invite links with QR codes, favourites, room filter, room history export (txt/json/html)",
+      "Room activity &amp; mod log, stats panel, server ACL editor, policy-list viewer",
+      "Room widgets, with a permission prompt before a widget may read or send in the room"
+    ]
+  }
+]