initial data-ingestion refactor

DATA-INGESTION-REFACTOR-SUMMARY.md

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+# Data-Ingestion Service Refactor Summary
+
+## What Was Done
+
+Successfully refactored the `data-ingestion` service to use the new connection pool pattern, completely removing dependencies on the singleton anti-pattern.
+
+### Key Changes
+
+1. **Service Container Setup**
+   - Created `database-setup.ts` with proper connection factory configuration
+   - Configured appropriate pool sizes for data ingestion workloads
+   - Added optional dynamic pool sizing for production environments
+
+2. **Main Service Refactor** (`index.ts`)
+   - Removed `connectMongoDB()` and `connectPostgreSQL()` singleton calls
+   - Replaced with `setupServiceContainer()` initialization
+   - Updated shutdown handlers to dispose container properly
+   - Routes now have access to the service container
+
+3. **Handler Updates**
+   - All handlers now accept `ServiceContainer` parameter
+   - QM handler operations use container-based OperationContext
+   - IB, Proxy, and WebShare handlers updated to accept container
+   - Added proper resource disposal with `ctx.dispose()`
+
+4. **Route Refactoring**
+   - Created `create-routes.ts` factory function
+   - Routes can access container through Hono context
+   - Maintains backward compatibility for simple routes
+
+5. **Migration Helper**
+   - Created temporary migration helper for legacy operations
+   - Provides `getMongoDBClient()` for IB operations still being migrated
+   - Includes cleanup in shutdown sequence
+
+### Configuration Changes
+
+- Added `@stock-bot/connection-factory` dependency
+- Updated `tsconfig.json` with proper references
+- Pool sizes optimized for data ingestion:
+  - MongoDB: 50 connections (batch imports)
+  - PostgreSQL: 30 connections
+  - Cache: 20 connections
+
+### Benefits Achieved
+
+1. **No More Global State**: Each service manages its own connections
+2. **Better Resource Management**: Proper cleanup on shutdown
+3. **Scalability**: Dynamic pool sizing for production workloads
+4. **Monitoring**: Pool metrics available for observability
+5. **Testing**: Easier to test with mock containers
+6. **Gradual Migration**: Legacy operations still work during transition
+
+### Next Steps
+
+1. **Complete Operation Migration**: Update IB operations to use container
+2. **Remove Migration Helper**: Once all operations are migrated
+3. **Add Monitoring**: Set up dashboards for pool metrics
+4. **Performance Testing**: Validate pool sizes under load
+5. **Replicate Pattern**: Apply same refactor to other services
+
+### Example Usage
+
+```typescript
+// Handler with container
+export function initializeHandler(container: ServiceContainer) {
+  const config = {
+    operations: {
+      'my-operation': createJobHandler(async (payload) => {
+        // Operation uses container
+        const ctx = OperationContext.create('handler', 'operation', { container });
+        try {
+          // Use databases through context
+          await ctx.mongodb.insertOne(data);
+          await ctx.postgres.query('...');
+          return { success: true };
+        } finally {
+          await ctx.dispose(); // Clean up resources
+        }
+      })
+    }
+  };
+}
+```
+
+### Migration Checklist
+
+- [x] Remove singleton imports from index.ts
+- [x] Create service container setup
+- [x] Update all handlers to accept container
+- [x] Create route factory with container access
+- [x] Add migration helper for legacy code
+- [x] Update shutdown handlers
+- [x] Test build successfully
+- [ ] Migrate remaining operations
+- [ ] Remove migration helper
+- [ ] Deploy and monitor