feat(diary): boot list, help and completion requests quietly (quick-261028-rqc)

- helpOnly also counts no command word, list, help, cobra's shell
  completion requests and --help=<bool>, read the way pflag does
- TestHelpOnlyAgreesWithCobra pins the classification against bonfire's
  real dispatch, with the passthrough --help case as the exception
- console and logging docs describe which invocations boot quietly

docs/services/logging.md

@@ -142,6 +142,8 @@ var blogLog = diary.For("blog")
 
 Its records carry `component=blog`, follow `log.components.blog` and go through the redacting channels.
 
+`Register` and `Boot` run before every command, so a plugin logs what it registered or collected at Debug (visible with `-vv`) rather than Info. Only the invocations that just ask for help (no command, `list`, `help`, `--help` or `-h`, shell completion) boot with the console at warnings; `migrate`, `queue:work` and one-off commands print every Info record a plugin logs while it boots.
+
 Redaction is a safety net for mistakes, not a way to log secrets on purpose. Log identifiers and outcomes: the record id, the vendor, the status code, how long it took. Never log request arguments, tokens, credentials or request and response bodies, which can carry personal data the patterns do not recognise.
 
 ## Request log