Add link previews, voice tiles and a menu volume slider; tidy the profile

- Link previews for web links in chat, fetched by the f0ckm upload host by
  default (linked sites never see the user's IP), or directly, or off
- Voice channel tiles above the chat on windows too narrow for the member list
- Per-person volume slider in the user context menu
- Profile panel: channel on its own line under the name, no Guest badge,
  voice actions moved to the context menu
- User information dialog refreshes every second
- Rate limiting mirrors Murmur's whole-second bucket leak, so irregular
  bursts are queued instead of dropped
- CHANGELOG.md

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CHANGELOG.md

@@ -0,0 +1,29 @@
+# Changelog
+
+All notable changes to mumh5. Versions follow the `version` in `package.json`.
+
+## Unreleased
+
+### Added
+
+- Link previews in chat: title, description and image for web links (up to two per message). By default they are fetched by your f0ckm upload host, so the linked sites never see your IP address. Can be switched to "fetched by this computer" or off in Settings, Chat and files.
+- Voice tiles on small windows: when the window is too narrow for the member list, the people in your voice channel appear as tiles above the chat, light up while they talk, and keep mute and deafen at hand. The tiles can be collapsed.
+- Per-person volume slider (0 to 300%) directly in the user context menu. Double-click resets it to 100%.
+
+### Changed
+
+- Profile panel: the current channel sits on its own line under the name, and the badge row wraps on narrow panels.
+- Profile panel: guests no longer get a "Guest" badge; registered users keep the "Registered" badge.
+- Profile panel: volume, "mute for me" and nickname moved to the user context menu, which has them for every place a user appears.
+- User context menu: "Information" moved to the end of the menu.
+- User information dialog updates every second, so online and idle times tick live.
+- Channel tree: channels no longer show an icon in front of the name; only channels you cannot enter show a lock.
+- Channel details header without the channel icon.
+
+### Fixed
+
+- Messages sent in quick, irregular bursts could still be dropped by the server's rate limit. The client now mirrors Murmur's bucket exactly (it only leaks whole seconds and restarts its timer on every message) and queues instead of losing messages.
+
+## 0.1.0
+
+- Initial version.