feat(sat): add CFDI XML parser service (Phase 4)

- Add sat-parser.service.ts for processing SAT packages:
  - Extract XML files from ZIP packages
  - Parse CFDI 4.0 XML structure with proper namespace handling
  - Extract fiscal data: UUID, amounts, taxes, dates, RFC info
  - Map SAT types (I/E/T/P/N) to application types
  - Handle IVA and ISR retention calculations
- Install @nodecfdi/cfdi-core dependency

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

apps/api/package.json

@@ -15,6 +15,7 @@
   },
   "dependencies": {
     "@horux/shared": "workspace:*",
+    "@nodecfdi/cfdi-core": "^1.0.1",
     "@nodecfdi/credentials": "^3.2.0",
     "@prisma/client": "^5.22.0",
     "adm-zip": "^0.5.16",