Add Papyrus sync scripts and proxy spawn refactor

Add new Papyrus scripts (CoSync.psc, CoSyncPlayer.psc, CoSyncQuest.psc) providing native bindings and quest/player proxy logic for networking: connection/session APIs, entity management, world/weather/workshop/companion sync, consumable/pipboy/door/power-armor events, and proxy animation/initialization handlers. Refactor the proxy actor controller (F4TProxyActorController.cpp) to support dynamic/runtime proxy spawning and improved lifecycle/visibility handling: change proxy base/form IDs to COPlayerProxy/CommonwealthOnline, add process-list actor lookup, spawn helpers, play-space/cell checks, 3D visibility refresh, ActorHandle usage, and spawn mutexes and globals for safer spawning. Update docs and setup (architecture.md, limitations.md, plugin/setup.md) to describe global dynamic spawn behavior, max runtime proxies (kMaxRuntimeProxyActors = 4), and validation checklist; update launch-two-fallout4.bat to show instance log locations. Misc: small tweaks to logging and debug flags to gate diagnostics.

plugin/setup.md

@@ -115,14 +115,22 @@ Use this checklist for the first plugin test:
 * [ ] Plugin log shows `[LocalPlayerId=N] Assigned server playerId: N`
 * [ ] Plugin logs prefixed remote player updates from another connected client
 * [ ] Plugin logs prefixed remote player removal after a disconnect
-* [ ] `Fallout4Together_Test.esp` is enabled
-* [ ] `coc F4TTestCell01` places the local player in the test cell
-* [ ] `F4TProxyRemotePlayer01REF` resolves in the test cell
-* [ ] With two Fallout 4 instances in `F4TTestCell01`, each instance moves its
-      local proxy to the other player's networked position
+* [ ] `CommonwealthOnline.esp` is enabled (provides `COPlayerProxy` actor base, local FormID `001733`)
+* [ ] With two Fallout 4 instances in the same cell, each instance spawns a dynamic
+      proxy at the other player's networked position
+* [ ] Optional regression: `coc F4TTestCell01` with `kEnablePrePlacedProxyPool` enabled
+* [ ] Optional regression: `F4TProxyRemotePlayer01REF` resolves when placed fallback flag is on
+
+### Global dynamic spawn validation
+
+* [ ] Two clients in the same vanilla interior (e.g. Sanctuary house) see each other's proxies
+* [ ] Two clients in the Commonwealth exterior in the same loaded area see proxies
+* [ ] Remote player in a different cell: proxy held hidden, not visible
+* [ ] Local player walks into remote player's cell: proxy spawns at remote position
+* [ ] Local player leaves a cell with active proxies: no orphaned actors remain in prior cell
 
 ## Notes
 
-Remote actor spawning is intentionally not part of the current prototype. The
-receive loop stores plain remote-player state, and the game-thread proxy actor
-controller consumes a copied snapshot to move the one placed test proxy actor.
+Remote actors are dynamically spawned at runtime in the local player's current
+cell. The game-thread proxy actor controller consumes a copied remote-player
+snapshot to spawn, move, and hold proxy actors per remote `playerId`.

plugin/src/main.cpp

@@ -53,6 +53,7 @@ namespace
 	};
 
 	constexpr auto kTransformSendInterval = 100ms;
+	constexpr auto kIdleTransformHeartbeatInterval = 2s;
 	constexpr auto kTransformLogInterval = 1s;
 	constexpr auto kTransformSendPositionThreshold = 3.0F;
 	constexpr auto kTransformSendRotationThreshold = 0.02F;
@@ -524,13 +525,16 @@ namespace
 		const auto isSpecialMovement = movementType != std::string_view{ "normal" };
 		const auto hasMeaningfulTransformDelta = HasMeaningfulTransformDelta(lastSentTransform, currentTransform);
 		const auto hasMovementStateChanged = HasMovementStateChanged(lastSentMovementState, networkMovementState);
-		if (!isSpecialMovement && !hasMeaningfulTransformDelta && !hasMovementStateChanged) {
+		const auto idleHeartbeatDue = (currentTime - lastSendTime) >= kIdleTransformHeartbeatInterval;
+		if (!isSpecialMovement && !hasMeaningfulTransformDelta && !hasMovementStateChanged && !idleHeartbeatDue) {
 			lastDebugSampleTransform = currentTransform;
 			lastDebugSampleTime = currentTime;
 			return;
 		}
 
-		if (!isSpecialMovement && currentTime - lastSendTime < kTransformSendInterval) {
+		if (!isSpecialMovement && !hasMeaningfulTransformDelta && !hasMovementStateChanged) {
+			// Idle heartbeat: keep remote clients updated even when both players are standing still.
+		} else if (!isSpecialMovement && currentTime - lastSendTime < kTransformSendInterval) {
 			return;
 		}