feat: upgrade claude-agent-sdk to 0.2.38 and adapt to new SDK types (#113)

* feat: upgrade claude-agent-sdk to 0.2.38 and adapt to new SDK types

- Bump @anthropic-ai/claude-agent-sdk from 0.1.x to 0.2.38 (both root and mcp-server)
- Bump zod from 3.x to 4.x (SDK peer dependency)
- Add allowDangerouslySkipPermissions to query options (required for bypassPermissions)
- Suppress new SDK message types (tool_progress, tool_use_summary, auth_status)
- Use structured error field on assistant messages instead of text-sniffing
- Add stop_reason to result message handling for diagnostics
- Add SDKAssistantMessageError type matching SDK's string literal union

* chore: remove CLAUDE_CODE_MAX_OUTPUT_TOKENS from all config and docs

README.md

@@ -119,12 +119,10 @@ cd shannon
 
 # Option A: Export environment variables
 export ANTHROPIC_API_KEY="your-api-key"              # or CLAUDE_CODE_OAUTH_TOKEN
-export CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000           # recommended
 
 # Option B: Create a .env file
 cat > .env << 'EOF'
 ANTHROPIC_API_KEY=your-api-key
-CLAUDE_CODE_MAX_OUTPUT_TOKENS=64000
 EOF
 
 # 3. Run a pentest