feat: add stack management and container delete endpoints

- Add stack compose YAML get/update endpoints
- Add stack environment variable get/update endpoints
- Add stack deploy and rebuild endpoints
- Add container delete endpoint with force option
- Add Portainer client methods for new operations
- Add comprehensive test coverage (30 new tests)
- Remove REQUESTED_SERVICES.md (now implemented)

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

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

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "core-api"
-version = "1.2.1"
+version = "1.3.0"
 description = "Core Code API - Infrastructure management and tools API"
 readme = "README.md"
 requires-python = ">=3.12"