Add builds await-processing, workflow build tracking, and processing-aware attach

- Add builds await-processing command to poll until a build finishes processing
- Track uploaded build version across workflow steps via lastUploadedBuildVersion
- attach-latest-build now waits for a just-uploaded build to appear and process
- attach-latest-build prompts to wait when the latest build is still processing
- Shared awaitBuildProcessing helper eliminates duplicated polling logic
- Dot-based progress indicator for builds not yet available in the API
- Note on builds list about recently uploaded builds taking time to appear
- Bump version to 0.2.1

CLAUDE.md

@@ -84,6 +84,7 @@ asc-client builds list [--bundle-id <id>]                         # List builds
 asc-client builds archive [--workspace X] [--scheme X] [--output X]  # Archive Xcode project
 asc-client builds upload [file]                                   # Upload build via altool
 asc-client builds validate [file]                                 # Validate build via altool
+asc-client builds await-processing <bundle-id> [--build-version X]  # Wait for build to finish processing
 asc-client run-workflow <file> [--yes]                            # Run commands from a workflow file
 ```