feat(framework): server testing utils, transaction storage simplify, pathfinding tests (#384)

## Server Testing Utils
- Add TestServer, TestClient, MockRoom for unit testing
- Export testing utilities from @esengine/server/testing

## Transaction Storage (BREAKING)
- Simplify RedisStorage/MongoStorage to factory pattern only
- Remove DI client injection option
- Add lazy connection and Symbol.asyncDispose support
- Add 161 unit tests with full coverage

## Pathfinding Tests
- Add 150 unit tests covering all components
- BinaryHeap, Heuristics, AStarPathfinder, GridMap, NavMesh, PathSmoother

## Docs
- Update storage.md for new factory pattern API

.changeset/transaction-storage-simplify.md

@@ -0,0 +1,48 @@
+---
+"@esengine/transaction": major
+---
+
+## Breaking Changes
+
+### Storage API Simplification
+
+RedisStorage and MongoStorage now use **factory pattern only** for connection management. The direct client injection option has been removed.
+
+**Before (removed):**
+```typescript
+// Direct client injection - NO LONGER SUPPORTED
+const storage = new RedisStorage({ client: redisClient });
+const storage = new MongoStorage({ client: mongoClient, database: 'game' });
+```
+
+**After (factory pattern only):**
+```typescript
+// RedisStorage
+const storage = new RedisStorage({
+    factory: () => new Redis('redis://localhost:6379'),
+    prefix: 'tx:',
+    transactionTTL: 86400,
+});
+
+// MongoStorage
+const storage = new MongoStorage({
+    factory: async () => {
+        const client = new MongoClient('mongodb://localhost:27017');
+        await client.connect();
+        return client;
+    },
+    database: 'game',
+});
+```
+
+### New Features
+
+- **Lazy Connection**: Connection is established on first operation, not at construction time
+- **Automatic Cleanup**: Support `await using` syntax (TypeScript 5.2+) for automatic resource cleanup
+- **Explicit Close**: Call `storage.close()` when done, or use `await using` for automatic disposal
+
+### Migration Guide
+
+1. Replace `client` option with `factory` function
+2. Add `storage.close()` call when done, or use `await using`
+3. For MongoStorage, ensure factory returns a connected client