Add tsk links command for listing and opening hyperlinks
Surfaces every link parsed from a task body — URLs (raw and markdown),
internal [[tsk-N]] refs, foreign [[ns-N]] refs — as a numbered list:
tsk links -T tsk-12
With -s, the list is piped through fzf and the picked link is opened
via the existing tsk follow path: URLs go to the system handler,
internal links are shown, foreign refs resolve through the configured
remote.
Test exercises the link parser directly to confirm all four link kinds
appear in the right order.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>