fix(app): order help sections consistently

[Pybsama]

Change summary

Fixes #1656.

This makes the help hierarchy consistent by displaying command-specific
sections before shared global flags:

• compact help now shows required/optional flags, arguments, and commands
  before global flags;
• verbose help now shows arguments and subcommands/commands before global
  flags;
• the auth guide and See Also footer remain after global flags.

The change only reorders the existing text templates. Flag classification,
command definitions, and JSON help output are unchanged.

All Submissions:

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes to Core Features:

• Have you written new tests for your core changes, as applicable?
• Have you successfully run tests with your changes locally?

Testing

• GOTOOLCHAIN=go1.25.7 go test -race -run '^TestHelpSectionOrder$' -count=50 ./pkg/app
• GOTOOLCHAIN=go1.25.7 go test -race -shuffle=on -count=10 ./pkg/app
• GOTOOLCHAIN=go1.25.7 make all

User Impact

Users see the same command-specific-first ordering in compact and verbose help,
while all existing help content remains available.

Are there any considerations that need to be addressed for release?

No breaking changes or special release steps.