test: add play tests for Blackjack and TicTacToe

Implement play tests for Blackjack and TicTacToe that simulate games
using various AI agents (Basic Strategy, Random, Greedy) and record
the results, decisions, and reactivity into playlogs for debugging
and LLM analysis. Update documentation to reflect the purpose of
these tests.

docs/testing-games.md

@@ -8,7 +8,9 @@
 
 ## Play tests
 
-Playtests are games executed with AI players who give unexpected play commands.
+The goal of playtests is to execute a game with AI players and potentially random seeds. Then the log/snapshots are read by the LLM agent to spot issues.
+
+There is no failure in play tests; all tests pass but the agent should read the log for reference.
 
 AI players are not LLMs here; they are typically common game AI implementations.
 
@@ -17,3 +19,5 @@ Create static functions that analyze the game state and return a command. Each s
 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.
+
+For each playtest attempt, generate a full game log, analyze and report what you find from the log.