Implement PlaceholderHelp component across various forms for enhanced user guidance

- Integrated PlaceholderHelp component into multiple forms including WelcomeForm, TagsManager, and StatsForm to provide contextual hints for available placeholders.
- Updated DiscordEmbedBuilder to support placeholder presets, improving user experience when creating embeds.
- Enhanced localization files to include new placeholder descriptions, ensuring clarity in both English and German.
- Refactored related components to maintain consistency in placeholder handling across the application.

apps/webui/src/messages/en.json

@@ -35,6 +35,33 @@
     "clear": "Clear embed",
     "clearHint": "Empty fields do not save an embed."
   },
+  "placeholders": {
+    "toggle": "Show available placeholders",
+    "hint": "Tap copy to insert. Only the placeholders listed here work in this field.",
+    "copy": "Copy placeholder",
+    "copied": "Placeholder copied",
+    "copyFailed": "Could not copy",
+    "desc": {
+      "userMention": "Mention of the member",
+      "userName": "Member display name",
+      "userTag": "Member username/tag",
+      "userId": "Member Discord ID",
+      "userDisplayName": "Display name (no mention)",
+      "userTagPlain": "Username without mention",
+      "username": "Member display name",
+      "server": "Server name",
+      "memberCount": "Current member count",
+      "args": "Arguments after the tag command",
+      "random": "Random choice from options (separated by |)",
+      "age": "Age in years (only if birth year is set)",
+      "level": "Reached level",
+      "count": "Current stats value",
+      "feedTitle": "Feed item title",
+      "feedUrl": "Feed item URL",
+      "channelBracket": "Channel mention (dashboard syntax — replace the ID)",
+      "channelNative": "Channel mention (Discord syntax — replace the ID)"
+    }
+  },
   "nav": {
     "dashboard": "Dashboard",
     "overview": "Overview",
@@ -268,11 +295,45 @@
       "retentionLabel": "Retention (days)",
       "retentionHint": "Delete cases and dashboard audit older than X days. 0 = keep forever.",
       "channelsTitle": "Event-channel mapping",
-      "channelsDescription": "Assign a dedicated log channel for each event type.",
+      "channelsDescription": "Pick a log channel and assign one or more event types to it.",
       "channelsEmpty": "No event-channel mappings configured.",
+      "channelsHint": "Each event type can only map to one channel. Selecting it here removes it from other rows.",
       "eventType": "Event type",
-      "channelId": "Channel ID",
-      "addMapping": "Add mapping"
+      "eventTypesLabel": "Event types",
+      "eventTypesPlaceholder": "Search event types…",
+      "channelId": "Log channel",
+      "addMapping": "Add mapping",
+      "errors": {
+        "duplicateEventType": "An event type is assigned more than once. Please check your selection."
+      },
+      "eventTypes": {
+        "MESSAGE_EDIT": "Message edited",
+        "MESSAGE_DELETE": "Message deleted",
+        "MESSAGE_BULK_DELETE": "Messages bulk deleted",
+        "MEMBER_JOIN": "Member joined",
+        "MEMBER_LEAVE": "Member left",
+        "MEMBER_BAN": "Member banned",
+        "MEMBER_UNBAN": "Member unbanned",
+        "MEMBER_UPDATE": "Member updated",
+        "CHANNEL_CREATE": "Channel created",
+        "CHANNEL_DELETE": "Channel deleted",
+        "CHANNEL_UPDATE": "Channel updated",
+        "VOICE_JOIN": "Voice joined",
+        "VOICE_LEAVE": "Voice left",
+        "VOICE_MOVE": "Voice moved",
+        "INVITE_CREATE": "Invite created",
+        "EMOJI_CREATE": "Emoji created",
+        "EMOJI_UPDATE": "Emoji updated",
+        "EMOJI_DELETE": "Emoji deleted",
+        "STICKER_CREATE": "Sticker created",
+        "STICKER_UPDATE": "Sticker updated",
+        "STICKER_DELETE": "Sticker deleted",
+        "THREAD_CREATE": "Thread created",
+        "THREAD_UPDATE": "Thread updated",
+        "THREAD_DELETE": "Thread deleted",
+        "GUILD_UPDATE": "Server updated",
+        "MOD_ACTION": "Moderation action"
+      }
     },
     "welcome": {
       "welcomeTitle": "Welcome",
@@ -287,7 +348,7 @@
       },
       "welcomeContent": "Message content",
       "contentPlaceholder": "Welcome {user} to {server}!",
-      "placeholdersHint": "Available placeholders: {user}, {user.name}, {user.tag}, {user.id}, {server}, {memberCount}",
+      "placeholdersHint": "Available placeholders: see the list below.",
       "welcomeEmbed": "Embed",
       "welcomeDmEnabled": "Welcome DM enabled",
       "dmContentPlaceholder": "Optional private message to new members",