feat(capture): record whole packets of an account, a character or everything on every server

Staff arm a packet capture on the dashboard; master passes MESSAGE_CAPTURE_CONTROL ARM to
every world, auth and chat and arms its own. Each server's PacketCapture tap (dServer receive,
and a send hook in RakPeer::Send so replica constructions are seen too) records into one
preallocated chunk per server and ships sealed chunks through master on the main loop when
capture_flush_bytes or capture_flush_interval_ms is reached; past capture_buffer_max_mb the
oldest chunks are dropped and the dashboard records a gap. Nothing is armed: one flag check.

- targets: an account (from its login; packets before the login are kept per connection
  and added once auth or the world knows whose they are), a character (from when it is
  picked), or everything; up to 8 at once (a bit each in the record mask)
- worlds and auth record their clients' packets and the master link messages of a captured
  player (session keys by name, zone transfers by request, player added/removed, migration);
  chat finds the player in each packet; master records server traffic for everything
- secrets are never recorded: structs that carry them (login request, login response user
  key, world validation session key, session key messages between servers) are read,
  blanked and written again before recording; auth keeps only the handshake and login
- PacketDecoder: a registry by service and message id names every packet and decodes the
  registered structs; CaptureBundle is the file format (DLUBNDL1, metadata, records);
  CaptureTools orders records on one timeline, pulls movement out, makes bundles portable
  or anonymous and diffs replays
- the dashboard keeps packet captures in message_capture_sessions (capture_kind 1) and
  their packets in a file under capture_dir, one write per batch; arming is audited
- MESSAGE_CAPTURE_CONTROL/DATA only gain appended enum values and trailing fields

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

dDashboardServer/routes/SettingsCatalog.cpp

@@ -429,6 +429,13 @@ namespace {
 		c.Add(Days("inspector_session_days", "Keep captures for", "0: no age limit.", "30"));
 		c.Add(Unit(Int(DASHBOARD, "inspector_max_mb", "At most", "When all saved captures together take more, the oldest are deleted. A busy 15 minute capture can take 50 MB. 0: no size limit.", "1024", 0, 1000000), "MB"));
 
+		c.AddSection("Packet capture", "How servers record packets for the dashboard's packet captures (docs/CaptureReplay.md). Nothing is written to disk per packet: "
+			"each server buffers records in memory and sends a batch when either limit below is reached; the dashboard writes one batch at a time to the capture's file.");
+		c.Add(Unit(Int(SHARED, "capture_flush_interval_ms", "Send at least every", "A server sends what it recorded this often, even when the batch is small.", "1000", 50, 60000), "ms"));
+		c.Add(Unit(Int(SHARED, "capture_flush_bytes", "Or when a batch reaches", "A server sends a batch as soon as it is this large.", "262144", 4096, 4194304), "bytes"));
+		c.Add(Unit(Int(SHARED, "capture_buffer_max_mb", "Keep at most", "Batches a server keeps while master can't take them; past this the oldest are dropped and the capture shows a gap.", "16", 1, 1024), "MB"));
+		c.Add(Format(Text(DASHBOARD, "capture_dir", "Capture files", "Folder for packet capture files, relative to the server binaries. Captures are player data: keep it out of any repository.", "captures"), eFormat::PATH));
+
 		c.AddSection("Economy history");
 		c.Add(Days("economy_detail_days", "Daily detail", "Older daily rows are merged into months.", "180", 31));
 		c.Add(Days("economy_map_days", "Map detail", "", "90", 31));