docs(skills): Bundling Resources with Skills page (new)

[Aaronontheweb]

Part of #95 · Group 1 · NEW skills/bundled-resources.md (Concept/Guide) · self-serve

Scope: references//scripts//assets/ layout; skill-md vs archive artifacts; deterministic archives with preserved Unix exec bits; the one-time automatic backfill; how netclaw downloads/SHA-256-verifies/extracts (zip-slip hardening); where resources land (~/.netclaw/skills/.server-feeds/<feed>/<skill>/); reading via skill_read_resource; running synced resources via shell.

Sources: docs/specs/skills.md:117-138, netclaw sync/extract code. Deps: #1 (light).

[Aaronontheweb]

Delivered in PR #106 (merged to dev as 4a4efa7 — src/content/docs/skills/bundled-resources.md). GitHub's auto-close only fired for #96; closing manually.