chore: update changelog for v0.2.3 with new features and improvements

docs/changelog/v0.2.3.md

@@ -3,6 +3,7 @@
 ## Features
 
 ### Moderation System
+
 - Added server roles: Owner, Admin, Mod, Member — first registered user is automatically Owner
 - New `/kick`, `/ban`, `/unban`, `/mute`, `/unmute`, `/role`, `/nuke` commands for moderators and admins
 - `ModerationController` with full REST API for role assignment, kicks, bans, mutes, message deletion, and channel nuking
@@ -12,6 +13,7 @@
 - Works for both SignalR and IRC connections; client shows an error dialog with the reason
 
 ### Private Channels
+
 - Channels can be created as public or private via a checkbox in the Create Channel dialog
 - Public channels are visible to all users; private channels only appear for members who joined them
 - Persistent channel membership tracked in the database (`ChannelMembership` table)
@@ -19,6 +21,7 @@
 - Channel creators are automatically added as members
 
 ### OpenGraph Link Embeds
+
 - Messages containing URLs now show a rich preview below the message text
 - Multiple URLs per message supported (up to 3) — each gets its own embed
 - Server-side fetching: detects URLs in a message, fetches each page, and parses OpenGraph meta tags (`og:title`, `og:description`, `og:site_name`)
@@ -30,26 +33,31 @@
 - SSRF protection rejects private/loopback IP addresses before fetching
 
 ### Notification Sounds
+
 - Incoming messages play a notification sound when the terminal is not focused
 - Embedded MP3 asset with cross-platform playback support
 
 ### Online Users Panel
+
 - Collapsible right-side panel showing online users in the current channel (toggle with F2)
 - Users displayed with status indicators, role badges, and their custom nickname colors
 - Panel updates on join, leave, and status change events
 
 ### @mention Highlighting
+
 - `@username` text rendered in orange accent color in all messages
 - Messages mentioning the current user get a full-line amber background highlight
 - Works across multi-line messages and continuation lines
 
 ### ASCII Art Improvements
+
 - Half-block character rendering (`▀`/`█`) with separate foreground + background colors for 2x vertical resolution
 - Switched from ANSI escape codes to printable color tags (`{F:RRGGBB}`, `{B:RRGGBB}`, `{X}`) — no control bytes in stored content
 - Optional size parameter for `/send` command: `-s` (40x40), `-m` (80x80, default), `-l` (120x120)
 - IRC gateway converts color tags back to ANSI for IRC client compatibility
 
 ### Client UI
+
 - Version number shown in the status bar
 - Custom colored rendering for channel list (active indicator, unread count badges)
 - Avatar upload field added to the profile edit dialog (file path or URL)