feat(api): add endpoint to list community prefixes with pagination

Introduced a new GET endpoint `/v1/communities/{id}/prefixes` to retrieve unique prefixes associated with a community, including pagination support via cursor and limit parameters. Updated OpenAPI documentation to reflect this addition. Implemented backend logic in both PostgreSQL and in-memory storage to handle the new functionality, ensuring proper authorization checks and response formatting.

internal/repository/postgres.go

@@ -1252,6 +1252,91 @@ func (p *Postgres) GetCommunity(tenantID, id string) (*store.Community, error) {
 	return &c, nil
 }
 
+func (p *Postgres) ListCommunityPrefixes(tenantID, communityID, cursor string, limit int) ([]store.PrefixRow, string, bool, error) {
+	if _, err := p.GetCommunity(tenantID, communityID); err != nil {
+		return nil, "", false, err
+	}
+	if limit <= 0 {
+		limit = 500
+	}
+	if limit > 5000 {
+		limit = 5000
+	}
+	off := 0
+	if cursor != "" {
+		if n, err := strconv.Atoi(cursor); err == nil && n >= 0 {
+			off = n
+		}
+	}
+	ctx := context.Background()
+	useSnap := prefixSnapshotTableExists(ctx, p.pool)
+	var rows pgx.Rows
+	var err error
+	if useSnap {
+		rows, err = p.pool.Query(ctx, `
+			WITH latest AS (
+				SELECT DISTINCT ON (module_id) id, prefix_snapshot_id
+				FROM config_revision
+				WHERE tenant_id = $1::uuid AND module_id IS NOT NULL
+				ORDER BY module_id, created_at DESC
+			),
+			combined AS (
+				SELECT rmp.prefix::text AS prefix, COALESCE(rmp.source, '') AS source
+				FROM revision_materialized_prefix rmp
+				JOIN latest l ON l.id = rmp.revision_id
+				WHERE l.prefix_snapshot_id IS NULL AND rmp.community_id = $2::uuid
+				UNION
+				SELECT psr.prefix::text, COALESCE(psr.source, '')
+				FROM prefix_snapshot_row psr
+				JOIN latest l ON l.prefix_snapshot_id = psr.snapshot_id
+				WHERE l.prefix_snapshot_id IS NOT NULL AND psr.community_id = $2::uuid
+			)
+			SELECT prefix, source FROM combined
+			ORDER BY prefix
+			LIMIT $3 OFFSET $4`, tenantID, communityID, limit+1, off)
+	} else {
+		rows, err = p.pool.Query(ctx, `
+			WITH latest AS (
+				SELECT DISTINCT ON (module_id) id
+				FROM config_revision
+				WHERE tenant_id = $1::uuid AND module_id IS NOT NULL
+				ORDER BY module_id, created_at DESC
+			)
+			SELECT DISTINCT rmp.prefix::text, COALESCE(rmp.source, '')
+			FROM revision_materialized_prefix rmp
+			JOIN latest l ON l.id = rmp.revision_id
+			WHERE rmp.community_id = $2::uuid
+			ORDER BY 1
+			LIMIT $3 OFFSET $4`, tenantID, communityID, limit+1, off)
+	}
+	if err != nil {
+		return nil, "", false, err
+	}
+	defer rows.Close()
+	var all []store.PrefixRow
+	comm := communityID
+	for rows.Next() {
+		var pr store.PrefixRow
+		if err := rows.Scan(&pr.Prefix, &pr.Source); err != nil {
+			continue
+		}
+		pr.CommunityID = &comm
+		all = append(all, pr)
+	}
+	more := len(all) > limit
+	if more {
+		all = all[:limit]
+	}
+	next := ""
+	if more {
+		next = fmt.Sprintf("%d", off+limit)
+	}
+	if len(all) == 0 {
+		return nil, "", false, nil
+	}
+	return all, next, more, nil
+}
+
 func (p *Postgres) CreateCommunity(tenantID string, in *store.Community) (*store.Community, error) {
 	if in == nil {
 		return nil, store.ErrInvalidInput