ca7c0e391e
runBunInstallWithDetails() defaulted to outputMode:"inherit", causing bun install stdout/stderr to leak into the TUI when callers omitted the option. Changed default to "pipe" so output is captured silently. Also fixed stale mock in background-update-check.test.ts: the test was mocking runBunInstall (unused) instead of runBunInstallWithDetails, and returning boolean instead of BunInstallResult.