Richer feeds / show status (counts, size, pending)

[frarredondo]

Summary

feeds and show give limited operational visibility for a multi-feed library.

Motivation / evidence

With hundreds of episodes per feed and overnight --all syncs, it’s hard to see pending work, failures, and disk usage at a glance.

Proposal

Extend status output to include, where available:

• episode counts (done / pending / failed)
• on-disk transcript size per feed
• last sync / last transcribed time
• clearer pending queue summary for long runs

Out of scope

Web dashboard, live progress UI beyond terminal output.

Acceptance criteria

• podtx feeds and/or podtx show surface counts and pending state clearly
• Output stays readable in a normal terminal width
• Docs / --help updated