feat: Add multiplayer networking architecture and documentation updates

- Updated Master Blueprint Index to include Multiplayer Networking support.
- Added detailed Multiplayer Networking sections across all developer documentation (01-11).
- Introduced authority maps, key patterns, and RPC guidelines for each system.
- Established a comprehensive multiplayer networking architecture document outlining core principles, replication strategies, and anti-cheat considerations.
- Enhanced UI documentation to clarify local-only behavior and binding to replicated dispatchers.
- Implemented client prediction strategies and RPC naming conventions for consistency across the framework.

docs/blueprints/02-player/12_BPC_HidingSystem.md

@@ -321,6 +321,30 @@ flowchart TD
 - The LOS trace channel should be custom (e.g., DetectionChannel) to ignore small props.
 - Breath-hold mechanic adds depth to stealth gameplay near enemies.
 - For multiplayer: only the hiding player knows their state; other players see a generic "occupado" on the spot.
+
+---
+
+## 11. Multiplayer Networking (Expanded)
+
+### Server RPCs
+| RPC | Direction | Description |
+|-----|-----------|-------------|
+| `Server_EnterHideSpot` | Client→Server | Client requests entering hide spot. Server validates slot availability, proximity. |
+| `Server_ExitHideSpot` | Client→Server | Client requests exiting. Server validates, teleports player, replicates. |
+| `Server_StartPeek` | Client→Server | Client starts peeking. Server validates peek ability, starts duration timer. |
+| `Server_StopPeek` | Client→Server | Client stops peeking. Server returns to Hidden state. |
+| `Server_TryBreathHold` | Client→Server | Client holds breath. Server validates, applies noise reduction on server. |
+
+### Authority
+- `EnterHideSpot`, `ExitHideSpot` are server-authoritative.
+- `IsPlayerDetectable` is server-only — AI runs on server.
+- `PerformLOSCheck` runs on server; results multicast to clients for UI feedback.
+- `ForceKickFromHide` is server-only (triggered by enemy discovery / damage).
+
+### Client Prediction
+- Enter/exit animations: client predicts; server confirms via replicated `CurrentHideState`.
+- Peek: camera offset is local; state replicated.
+- Hide spot occupation: `I_HidingSpot.OccupantPawn` is replicated — other clients see "Occupied".
 - Hide spots with bBlocksStress = true can double as narrative safe rooms.
 
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