WIP: Add input broadcasting and client-side prediction features

Changes include:
- Client: INPUT_BROADCAST packet handling and opponent prediction rendering
- Client: Protocol parsing for INPUT_BROADCAST packets
- Server: Input broadcasting to all clients except sender

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.claude/settings.local.json

@@ -0,0 +1,12 @@
+{
+  "permissions": {
+    "allow": [
+      "Read(//g/Coding/code2/**)",
+      "Bash(python -m py_compile server/server.py)",
+      "Bash(node --check client/client.js)",
+      "Bash(node --check client/protocol.js)"
+    ],
+    "deny": [],
+    "ask": []
+  }
+}