[FEATURE] /release-notes should show only last 10 versions by default

Problem

The /release-notes command outputs notes for all versions, making the output very verbose. This causes noticeable lag when scrolling through the results in the terminal, especially on long histories.

Proposed solution

• Default /release-notes to showing only the last 10 versions
• For older releases, display a link pointing to the GitHub repository's release notes page (e.g., https://github.com/anthropics/claude-code/releases) so users can browse the full history there

Alternatives considered

None — the current behavior is to dump everything, which doesn't scale well as releases accumulate.

Priority

Medium

Category

CLI commands and flags