feat(oecs): improve serialization and add snapshot tests

Enhance the OECS framework to support more robust component
deserialization during world serialization. This includes adding
boxed component support and a runtime fallback for component
discovery.

Additionally, introduces snapshot testing patterns for Blackjack
and TicTacToe to allow for manual verification of world state and
reactivity logs.

docs/testing-games.md

@@ -1,7 +1,19 @@
 # Testing games
 
 1. Games are dlls. Use a standalone test project to test a game.
-2. Create baseline game snapshots in textual format.
-3. Create baseline logs via the r3 observable api.
+2. Create baseline game snapshots in textual format. Save to files.
+3. Create baseline logs via the r3 observable api. Save to files.
 4. Read the snapshot/logs manually to identify issues.
 5. Make sure serialization roundtrip works.
+
+## Play tests
+
+Playtests are games executed with AI players who give unexpected play commands.
+
+AI players are not LLMs here; they are typically common game AI implementations.
+
+Create static functions that analyze the game state and return a command. Each such function is an agent. Each AI player routes its decisions to a random agent in a pool of weighted agents.
+
+Agents to consider:
+- Random: evenly chooses every move randomly.
+- Greedy: uses a specific way to score actions. Always chooses the onewith highest score. There can be multiple Greedy agents wtih different scoring.