commands: Fix --panicOnWarning flag having no effect with module version warnings
The --panicOnWarning flag was not wired into the root command's logger,
so warnings emitted during config loading (such as module version
incompatibility warnings) would not trigger a panic.
Bind the panicOnWarning flag to the rootCommand struct and set the
PanicOnWarningHook on the logger created in createLogger.
Fixes #14524
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>