T6: expand telemetry to T5-parity reports and add .join module

- Telemetry: async queued game_start/heartbeat/round_change/game_end with
  sequenced FIFO, watchdog, log-level dvar, and per-player stats snapshot
- Join: new tws_t6_join.gsc chat command lets late spectators enter mid-match
- Update NOTES/README/check.ps1 to reflect the six-module layout

t6/tws_t6_join.gsc

@@ -0,0 +1,116 @@
+/* tws_t6_join.gsc - .join lets a newcomer leave spectator mode before round end. */
+
+#include maps\mp\_utility;
+#include common_scripts\utility;
+
+// Plutonium probes both entry points; runtime setup belongs in init.
+main()
+{
+    println("[tws_t6_join] main reached");
+}
+
+init()
+{
+    println("[tws_t6_join] init reached");
+
+    scripts\zm\tws_t6_common::ensure_config();
+    scripts\zm\tws_t6_common::register_spawn_handler(::join_spawn);
+
+    level thread join_chat_listener();
+}
+
+// Never reset this on death or round change. Spectator spawns do not count.
+join_spawn()
+{
+    self.tws_join_has_played = true;
+}
+
+join_chat_listener()
+{
+    level endon("end_game");
+    level endon("game_ended");
+    level endon("intermission");
+
+    for (;;)
+    {
+        level waittill("say", message, player);
+
+        if (!isDefined(player) || !isDefined(message))
+            continue;
+
+        if (toLower(message) == ".join")
+            player thread join_request();
+    }
+}
+
+join_request()
+{
+    self endon("disconnect");
+    level endon("end_game");
+    level endon("game_ended");
+    level endon("intermission");
+
+    // The spawn handler flag is set on first playable spawn only; spectator
+    // spawns do not trigger it. Belt-and-suspenders against re-triggering.
+    if (is_true(self.tws_join_has_played) || is_true(self.tws_join_used))
+    {
+        self iPrintLnBold("^3.join is only for newcomers who have not played yet");
+        return;
+    }
+
+    // Fail closed while the stock connection setup is still in progress.
+    // T6 stock does not populate self.initialized the way T5 SP zombiemode
+    // does; use sessionstate as the readiness signal.
+    if (!isDefined(self.sessionstate) || self.sessionstate != "spectator")
+    {
+        self iPrintLnBold("^3.join is only available while waiting to enter the game");
+        return;
+    }
+
+    if (is_true(level.intermission) || is_true(level.gameended) ||
+        !isDefined(level.round_number) || level.round_number < 1 ||
+        !isDefined(level.spawnplayer) || !join_has_active_player())
+    {
+        self iPrintLnBold("^3The game is not ready for .join");
+        return;
+    }
+
+    // Late connections can miss the stock seeding of self.spectator_respawn
+    // (stock asserts it in spectator_respawn); pick a random map spawn point
+    // as a fallback so the stock callback can proceed.
+    if (!isDefined(self.spectator_respawn))
+    {
+        points = getstructarray("initial_spawn_points", "targetname");
+        if (!isDefined(points) || points.size == 0)
+        {
+            self iPrintLnBold("^3No spawn point available; wait for the next round");
+            return;
+        }
+
+        self.spectator_respawn = points[randomInt(points.size)];
+    }
+
+    // Match stock spectators_respawn setup. Preserve any map-specific
+    // spawn callback if another mod already installed one.
+    if (!isDefined(level.custom_spawnplayer))
+        level.custom_spawnplayer = maps\mp\zombies\_zm::spectator_respawn;
+
+    // Consume BEFORE entering stock code, which may yield. Repeated chat
+    // commands cannot start overlapping spawns or grant another life.
+    self.tws_join_used = true;
+    self [[level.spawnplayer]]();
+}
+
+join_has_active_player()
+{
+    players = getPlayers();
+    for (i = 0; i < players.size; i++)
+    {
+        player = players[i];
+        if (isDefined(player.sessionstate) && player.sessionstate == "playing" &&
+            isAlive(player) && !(player maps\mp\zombies\_zm_laststand::player_is_in_laststand()))
+            return true;
+    }
+
+    return false;
+}