add emil-design-eng skill to install/update pipeline

- Download SKILL.md from emilkowalski/skill to skills-external/
- Symlink to ~/.claude/skills/ via link.sh
- install-plugins.sh step 9: curl download + symlink check
- update-all.sh step 8: re-fetch latest SKILL.md on update
- plugins.lock.json: add emil-design-eng entry
- .gitignore: ignore auto-created symlink in skills/

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

plugins.lock.json

@@ -30,5 +30,11 @@
     "version": "latest",
     "managed_by": "pipx",
     "note": "Codebase knowledge graph. CLI is 'graphify'. Install: pipx install graphifyy && graphify install && graphify claude install. Adds PreToolUse hook for Glob/Grep."
+  },
+  "emil-design-eng": {
+    "source": "https://github.com/emilkowalski/skill",
+    "path": "skills/emil-design-eng/SKILL.md",
+    "managed_by": "curl",
+    "note": "Emil Kowalski's design engineering skill — UI polish, animations, component craft. Downloaded to skills-external/emil-design-eng/, symlinked by link.sh."
   }
 }