Remove unused scripts and utilities

Delete 18 dead code files:
- 9 main scripts (capture-tui-output, cleanup-builds, create-placeholder-packages, debug-layout, disable-v8-jit, install-bun, make-patch, verify-socketbin-packages, verify-stub-bundle)
- 6 utils (affected-test-mapper, common, interactive-runner, packages, path-helpers, suppress-warnings)
- 3 lib files (integrity-helpers, network-helpers, platform-helpers)

Author: jdalton