feat: sync skills from supabase/agent-skills v0.1.5 (#34)

Co-authored-by: Rodriguespn <44656907+Rodriguespn@users.noreply.github.com>

Author: github-actions[bot]

skills/supabase/SKILL.md

@@ -69,6 +69,9 @@ When working on any Supabase task that touches auth, RLS, views, storage, or use
 - **Storage access control**
   - **Storage upsert requires INSERT + SELECT + UPDATE.** Granting only INSERT allows new uploads but file replacement (upsert) silently fails. You need all three.
 
+- **Dependency and supply-chain security**
+  - **Always pin package versions and commit lockfiles** when installing Supabase packages (`supabase-js`, `@supabase/ssr`, `supabase-py`, etc.). See the [npm security guide](https://supabase.com/docs/guides/security/npm-security.md) for the full checklist.
+
 For any security concern not covered above, fetch the Supabase product security index: `https://supabase.com/docs/guides/security/product-security.md`
 
 ## Supabase CLI