feat(battle-sim): implement battle simulation logic and metrics tracking

- Added WarBattleMetrics interface to track attacker and defender skills during battles.
- Enhanced WarUnit class with method to log activated skills.
- Introduced environment setup for battle simulation, including unit set loading and configuration resolution.
- Developed in-memory and Redis transport layers for handling battle simulation requests and results.
- Created types and interfaces for battle simulation payloads and responses.
- Implemented battle simulation processing logic, including logging and skill tracking.
- Added tests for battle simulation processor to ensure functionality and correctness.

app/game-api/src/battleSim/unitSetLoader.ts

@@ -0,0 +1,53 @@
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+import { parseUnitSetDefinition, type UnitSetDefinition } from '@sammo-ts/logic';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const DEFAULT_UNIT_SET_ROOT = path.resolve(
+    __dirname,
+    '..',
+    '..',
+    '..',
+    'game-engine',
+    'resources',
+    'unitset'
+);
+
+export interface UnitSetLoaderOptions {
+    unitSetRoot?: string;
+    filePrefix?: string;
+}
+
+const readJsonFile = async (filePath: string): Promise<unknown> => {
+    const raw = await fs.readFile(filePath, 'utf8');
+    return JSON.parse(raw) as unknown;
+};
+
+const resolveUnitSetRoot = (options?: UnitSetLoaderOptions): string =>
+    options?.unitSetRoot ?? DEFAULT_UNIT_SET_ROOT;
+
+export const resolveUnitSetDefinitionPath = (
+    unitSetName: string,
+    options?: UnitSetLoaderOptions
+): string => {
+    const prefix = options?.filePrefix ?? 'unitset_';
+    return path.resolve(resolveUnitSetRoot(options), `${prefix}${unitSetName}.json`);
+};
+
+export const loadUnitSetDefinition = async (
+    unitSetPath: string
+): Promise<UnitSetDefinition> => {
+    const raw = await readJsonFile(unitSetPath);
+    return parseUnitSetDefinition(raw);
+};
+
+export const loadUnitSetDefinitionByName = async (
+    unitSetName: string,
+    options?: UnitSetLoaderOptions
+): Promise<UnitSetDefinition> => {
+    const unitSetPath = resolveUnitSetDefinitionPath(unitSetName, options);
+    return loadUnitSetDefinition(unitSetPath);
+};