fix: Add missing type field and pass build args to CI

- Add outOfStockProducts to StateMetrics interface
- Add onSpecialProducts to getStateSummary return
- Pass APP_GIT_SHA and other build args to docker build

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/multi-state/state-query-service.ts

@@ -121,6 +121,7 @@ export class StateQueryService {
       totalProducts: parseInt(metrics.totalProducts || '0', 10),
       inStockProducts: parseInt(metrics.inStockProducts || '0', 10),
       outOfStockProducts: parseInt(metrics.outOfStockProducts || '0', 10),
+      onSpecialProducts: parseInt(metrics.onSpecialProducts || '0', 10),
       uniqueBrands: parseInt(metrics.uniqueBrands || '0', 10),
       uniqueCategories: parseInt(metrics.uniqueCategories || '0', 10),
       avgPriceRec: metrics.avgPriceRec ? parseFloat(metrics.avgPriceRec) : null,