Backlog management

Capture single items to a project backlog, or list and triage an existing one. Detect the user's intent and run in either add mode (one item being filed) or review mode (looking at what's there). The two modes share destination detection.

Destination detection

Try in order; cache the result for any follow-up in the same flow:

1. gh repo view succeeds → use GitHub issues for that repo.
2. Else docs/BACKLOG.md exists → append for adds, read for reviews.
3. Else docs/issues/ directory exists → per-issue files (one .md per issue, numbered prefix).
4. Else ask the user where to put it. Don't silently create files in the project root.

If the user invokes this skill in a directory with no obvious project (no git, no docs/), say so and ask before doing anything.

Add mode

The user has a single item to file. Goal: lower ceremony than typing the issue themselves. If it's heavier than that, they'll stop using the skill.