Fix dotted canvas dashboard filenames

[nishantmonu51]

Summary

• Preserve dots in Rill resource names when deriving names from .yaml, .yml, and .sql file paths
• Keep legacy compound-extension stripping for non-resource data files
• Add regression coverage for dotted YAML/YML/SQL resource filenames

Test

• npm run test -w web-common -- entity-mappers.spec.ts --run
• npx prettier --check web-common/src/features/entity-management/entity-mappers.ts web-common/src/features/entity-management/entity-mappers.spec.ts