Add `sync_registry` to `skills/install.rs` that pulls `index.json` from the
configured `[skills] registry_url`, resolves each entry to a download URL,
checks ETag + SHA-256 for freshness, and writes SKILL.md (or the full
unpacked tarball) into `~/.deepseek/cache/skills/<name>/`. A `.cache-meta.json`
sidecar records the ETag and hash so subsequent syncs skip unchanged skills in
one round-trip.
Wire the new `/skills sync` slash-command in `commands/skills.rs` (dispatched
from `list_skills`) and update the `COMMANDS` usage string in `mod.rs` to
`/skills [--remote|sync]`. The per-skill failure model is non-fatal: the
command prints a per-entry `[+]`/`[=]`/`[!]` summary and returns a final
tally. `default_cache_skills_dir` and the new outcome types are re-exported
from `skills/mod.rs` for downstream consumers.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
wangfeng
5430e1a9c5