feat(bootstrapper): add --test-mode for resilient bootstrap processing

Add test mode that continues processing after build failures instead
of failing fast. Useful for testing build configurations across many
packages.

When enabled:
- Catches any exception during bootstrap
- Logs the error with full traceback
- Records the failed package name
- Continues to the next package
- Exits non-zero at completion if any failures

Closes #713

Co-Authored-By: Claude <claude@anthropic.com>

Signed-off-by: Lalatendu Mohanty <lmohanty@redhat.com>

Author: LalatenduMohanty

.gitignore

@@ -35,3 +35,4 @@ __pycache__/
 /.mypy_cache/
 .skip-coverage
 .claude
+/.beads/