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/10_BPC_StressSystem.md

@@ -337,6 +337,28 @@ flowchart TD
 - Stress tiers can gate narrative content — questgivers behave differently based on player stress.
 - Hallucination types can be configured via Data Asset (DA_HallucinationConfig).
 - For multiplayer: Stress is server-authoritative; clients receive tier changes for local effects.
+
+---
+
+## 11. Multiplayer Networking (Expanded)
+
+### Server RPCs
+| RPC | Direction | Description |
+|-----|-----------|-------------|
+| `Server_AddStress` | Client→Server | Client reports stress event. Server validates source, applies. |
+| `Server_AddStressSource` | Client→Server | Client enters enemy proximity zone. Server adds/updates source. |
+| `Server_RemoveStressSource` | Client→Server | Client leaves enemy zone. Server removes source. |
+| `Server_SetSafeZone` | Client→Server | Client reports safe zone status. Server validates, applies decay. |
+
+### Authority
+- **Server** calculates total stress from all sources, updates tier, replicates.
+- **Client** plays local hallucination/audio effects based on replicated tier.
+- `ForcePanic()` is server-only (narrative system calls it directly on server).
+
+### Client Prediction
+- Stress bar: predicted on client, corrected by `OnRep_CurrentStress`.
+- Hallucinations: randomly triggered by client based on replicated tier (cosmetic only).
+- Safe zone: server-authoritative; clients see OnSafeZoneChanged dispatcher.
 - The HealthDeficitMultiplier creates a death spiral feel — use carefully for horror pacing.
 - Safe zones double as narrative checkpoints and stress recovery areas.