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/INDEX.md

@@ -301,4 +301,10 @@ Below are the most cross-referenced systems — these are the ones the State Man
 
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-*Master Blueprint Index v3.0 — The single reference document for every file in the framework. Now 135 files with State Management + MetaSounds Audio systems.*
+*Master Blueprint Index v3.1 — The single reference document for every file in the framework. Now 135 files with State Management, MetaSounds Audio, and Multiplayer Networking support.*
+
+---
+
+## Multiplayer Networking
+
+See [`docs/architecture/multiplayer-networking.md`](../architecture/multiplayer-networking.md) for the full networking architecture specification. All blueprint specs include replication stubs, Server RPCs, and authority patterns. Developer docs include Multiplayer Networking sections per category.