fix(bots): intercept /confess so original never hits chat

Root cause of "not anonymous":
1. Confess deleted via raw SQL with no MESSAGE_DELETE broadcast
2. Frontend extractIds only accepted message_id, but deletes send id
   so live clients never removed deleted messages without refresh

Fix:
- Intercept /confess at message create: never store or broadcast the
  original; post only the anonymous bot message
- Accept both id and message_id on MESSAGE_DELETE in the WS store
- Include both fields on delete broadcasts

internal/bot/runner.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/json"
+	"fmt"
 	"log/slog"
 	"sync"
 
@@ -228,4 +229,104 @@ func (r *Runner) RegisteredTypes() []string {
 	return names
 }
 
+// TryConfess intercepts "/confess …" at message create time.
+// On success the original is never stored or broadcast (true anonymity).
+// Returns the anonymous bot message payload for the HTTP response when handled.
+func (r *Runner) TryConfess(ctx context.Context, serverID, _authorID, content string) (map[string]interface{}, bool) {
+	text, ok := parseConfessContent(content)
+	if !ok {
+		return nil, false
+	}
+
+	var botID, botName, ownerID string
+	var rawConfig string
+	err := r.db.QueryRowContext(ctx, `
+		SELECT b.id, b.name, b.owner_id, COALESCE(b.config::text, '{}')
+		FROM bots b
+		JOIN bot_servers bs ON bs.bot_id = b.id
+		WHERE bs.server_id = $1 AND b.bot_type = 'confess'
+		LIMIT 1
+	`, serverID).Scan(&botID, &botName, &ownerID, &rawConfig)
+	if err != nil {
+		return nil, false
+	}
+
+	var cfg ConfessConfig
+	if err := json.Unmarshal([]byte(rawConfig), &cfg); err != nil || cfg.ChannelID == "" {
+		return nil, false
+	}
+
+	// Ensure bot can post to the confession channel's server.
+	r.ensureBotServerFromConfig(botID, json.RawMessage(rawConfig))
+
+	anonContent := fmt.Sprintf("🕵️ **anonymous confession:** %s", text)
+	if len(anonContent) > 4000 {
+		anonContent = anonContent[:4000]
+	}
+
+	var msgID, createdAt string
+	err = r.db.QueryRowContext(ctx, `
+		INSERT INTO messages (channel_id, author_id, content, bot_id)
+		VALUES ($1, $2, $3, $4)
+		RETURNING id, created_at::text
+	`, cfg.ChannelID, ownerID, anonContent, botID).Scan(&msgID, &createdAt)
+	if err != nil {
+		r.logger.Error("confess: insert failed", "error", err)
+		return nil, false
+	}
+
+	targetServerID, err := r.hub.ServerIDForChannel(ctx, cfg.ChannelID)
+	if err != nil || targetServerID == "" {
+		targetServerID = serverID
+	}
+
+	payload := map[string]interface{}{
+		"id":                  msgID,
+		"channel_id":          cfg.ChannelID,
+		"author_id":           ownerID,
+		"author_username":     botName,
+		"author_display_name": nil,
+		"author_bot":          true,
+		"bot_id":              botID,
+		"bot_name":            botName,
+		"content":             anonContent,
+		"reply_to":            nil,
+		"edited_at":           nil,
+		"pinned":              false,
+		"created_at":          createdAt,
+		"embeds":              []interface{}{},
+		"reactions":           []interface{}{},
+	}
+
+	r.hub.BroadcastToServer(targetServerID, gateway.Event{
+		Type: gateway.EventMessageCreate,
+		Data: payload,
+	})
+
+	return payload, true
+}
+
+// DeleteMessage removes a message and broadcasts MESSAGE_DELETE to live clients.
+func (r *Runner) DeleteMessage(messageID string) {
+	var channelID string
+	err := r.db.QueryRowContext(context.Background(),
+		`DELETE FROM messages WHERE id = $1::uuid RETURNING channel_id`, messageID,
+	).Scan(&channelID)
+	if err != nil {
+		return
+	}
+	serverID, err := r.hub.ServerIDForChannel(context.Background(), channelID)
+	if err != nil || serverID == "" {
+		return
+	}
+	r.hub.BroadcastToServer(serverID, gateway.Event{
+		Type: gateway.EventMessageDelete,
+		Data: map[string]string{
+			"id":         messageID,
+			"message_id": messageID,
+			"channel_id": channelID,
+		},
+	})
+}
+