rpk: describe-storage help text omits tiered_cloud_topic from its cloud storage mode list

What's wrong

The long help for rpk topic describe-storage lists the possible cloud storage modes as:

one of disabled, write_only, read_only, full, read_replica, cloud_topic, and cloud_topic_read_replica

(src/go/rpk/pkg/cli/topic/describe_storage.go lines 293-294 at tag v26.2.2)

but tiered_cloud_topic is a real mode the same command both prints and special-cases:

• the same help text's SIZE section says "For tiered_cloud_topic, the local segment count is also shown" (line 313)
• the code branches on mode == "tiered_cloud_topic" (lines 172, 177), with the comment "Only a tiered_cloud_topic has a local log worth reporting segments for"

So a user cross-referencing the SIZE section's mention (or the command's own SUMMARY output) against the documented mode list finds a value the list says doesn't exist.

Suggested fix

Add tiered_cloud_topic to the mode list in the SUMMARY paragraph of the long help.

Context

Found while reviewing the v26.2.2 rpk docs regeneration (redpanda-data/docs#1966). The docs side is already corrected via a description override in docs-data/rpk-overrides.json, so this is about the CLI's own --help output, not the published reference pages.

Generated with Claude Code