feat: AI vs AI battle with multiple strategies

CLAUDE.md

@@ -12,6 +12,11 @@ make test-all          # All tests with verbose output
 make test-coverage     # Unit tests with coverage report
 make build             # Build binary
 make lint              # Static analysis (go vet)
+
+# AI Battle
+yatz battle                                    # Greedy vs Statistical (default)
+yatz battle --players "A:llm:personas/aggressive.md,D:llm:personas/defensive.md"
+yatz battle --rounds 100 --quiet               # 100-game statistics
 ```
 
 ## Testing Workflow
@@ -27,14 +32,15 @@ make lint              # Static analysis (go vet)
 ## Project Structure
 
 ```
-cmd/yatz/   Entry point (cobra subcommands: play, mcp, host, join, match)
-engine/     Pure game logic (state machine, scoring, dice, AI, GameClient interface)
-cli/        Interactive TUI (bubbletea v2)
+cmd/yatz/   Entry point (cobra subcommands: play, mcp, host, join, match, battle)
+engine/     Pure game logic (state machine, scoring, dice, AI, Strategy, Battle, GameClient interface)
+cli/        Interactive TUI (bubbletea v2) + AI battle spectator
 mcp/        MCP server for LLM integration (mcp-go, stdio transport)
 p2p/        P2P host-authority online play (length-prefixed JSON over TCP)
 match/      Matchmaking WebSocket client
 lambda/     Serverless matchmaking handler (AWS Lambda + API Gateway + DynamoDB)
-bot/        LLM bot integration (MCP config, system prompt, Claude API interaction)
+bot/        LLM bot integration (MCP config, system prompt, Claude API, LLM Strategy)
+personas/   Markdown-based AI persona definitions for LLM Strategy
 ```
 
 ## Key Design Decisions
@@ -45,6 +51,9 @@ bot/        LLM bot integration (MCP config, system prompt, Claude API interacti
 - **Host-authority model**: Host runs the game engine; guest sends actions over TCP and receives state updates.
 - **AI auto-play**: `LocalClient.Score()` triggers AI turns automatically via `runAITurns()`.
 - **Scorecard**: `map[Category]*int` where `nil` = unfilled, `*0` = filled with zero.
+- **Strategy pattern** (`engine/strategy.go`): `Strategy` interface abstracts AI decision-making. Implementations: `GreedyStrategy` (immediate best score), `StatisticalStrategy` (expected value), `LLMStrategy` (Claude API via `anthropic-sdk-go`).
+- **Battle engine** (`engine/battle.go`): `RunBattle()` drives AI-vs-AI games. `OnTurnDone` callback streams results to TUI spectator.
+- **LLM API Key**: `LLMStrategy` calls Claude API directly (not via MCP) for speed. Uses `--api-key` flag or `ANTHROPIC_API_KEY` env var.
 
 ## Dependencies
 
@@ -53,4 +62,5 @@ bot/        LLM bot integration (MCP config, system prompt, Claude API interacti
 - `mark3labs/mcp-go` — MCP server
 - `gorilla/websocket` — matchmaking client
 - `aws-lambda-go`, `aws-sdk-go-v2` — serverless matchmaking
+- `anthropic-sdk-go` — Claude API client for LLM Strategy
 - `stretchr/testify` — test assertions

README.md

@@ -52,6 +52,24 @@ yatz join 192.168.1.10:9876 --name Bob
 yatz match --server wss://your-api-gateway-url --name Alice
 ```
 
+### AI Battle
+
+Watch AI strategies compete against each other:
+
+```bash
+# Greedy vs Statistical (default)
+yatz battle
+
+# LLM persona battle (requires ANTHROPIC_API_KEY)
+yatz battle --players "Attacker:llm:personas/aggressive.md,Defender:llm:personas/defensive.md"
+
+# Run 100 games and compare statistics
+yatz battle --rounds 100 --quiet
+
+# Three-way battle with fixed seed
+yatz battle --players "G:greedy,S:statistical,L:llm" --seed 42
+```
+
 ## Commands
 
 | Command | Description |
@@ -61,6 +79,7 @@ yatz match --server wss://your-api-gateway-url --name Alice
 | `yatz host` | Host a P2P game |
 | `yatz join <addr>` | Join a P2P game |
 | `yatz match` | Find opponent via matchmaking |
+| `yatz battle` | Watch AI vs AI battle |
 
 ## Controls (TUI)
 
@@ -75,6 +94,29 @@ yatz match --server wss://your-api-gateway-url --name Alice
 - `p2p/` - P2P host-authority online play
 - `match/` - Matchmaking client
 - `lambda/` - Serverless matchmaking handler (AWS)
+- `bot/` - LLM bot integration (Claude API, LLM Strategy)
+- `personas/` - AI persona definitions (Markdown)
+
+## Personas
+
+Create custom AI personas as Markdown files:
+
+```markdown
+# My Custom AI
+## 性格
+Description of personality...
+
+## 戦略
+- Strategy point 1
+- Strategy point 2
+
+## 口癖
+「Catchphrase」
+```
+
+Use with: `yatz battle --players "MyAI:llm:path/to/persona.md"`
+
+Built-in personas: `personas/aggressive.md`, `personas/defensive.md`, `personas/gambler.md`
 
 ## Development
 

bot/persona.go

@@ -0,0 +1,80 @@
+package bot
+
+import (
+	"os"
+	"strings"
+)
+
+// Persona represents a loaded character persona from a markdown file.
+type Persona struct {
+	Name        string
+	Personality string
+	Strategy    string
+	Catchphrase string
+	Raw         string
+}
+
+// LoadPersona reads and parses a persona markdown file.
+// Format:
+//
+//	# Character Name
+//	## 性格
+//	...
+//	## 戦略
+//	...
+//	## 口癖
+//	...
+func LoadPersona(path string) (*Persona, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	raw := string(data)
+	p := &Persona{Raw: raw}
+
+	lines := strings.Split(raw, "\n")
+	var currentSection string
+	var sectionBuf strings.Builder
+
+	flushSection := func() {
+		content := strings.TrimSpace(sectionBuf.String())
+		switch currentSection {
+		case "name":
+			p.Name = content
+		case "性格", "personality":
+			p.Personality = content
+		case "戦略", "strategy":
+			p.Strategy = content
+		case "口癖", "catchphrase":
+			p.Catchphrase = content
+		}
+		sectionBuf.Reset()
+	}
+
+	for _, line := range lines {
+		trimmed := strings.TrimSpace(line)
+		if strings.HasPrefix(trimmed, "# ") && !strings.HasPrefix(trimmed, "## ") {
+			flushSection()
+			currentSection = "name"
+			sectionBuf.WriteString(strings.TrimPrefix(trimmed, "# "))
+			continue
+		}
+		if strings.HasPrefix(trimmed, "## ") {
+			flushSection()
+			currentSection = strings.ToLower(strings.TrimPrefix(trimmed, "## "))
+			continue
+		}
+		if currentSection != "" {
+			sectionBuf.WriteString(line)
+			sectionBuf.WriteString("\n")
+		}
+	}
+	flushSection()
+
+	if p.Name == "" {
+		p.Name = "LLM"
+	}
+
+	return p, nil
+}