fix: drop plugin.json 'skills' key to clear path-escape error on v2.1.109 (#264)

plugin.json has declared "skills": ["./"] unchanged since v2.1.0. That
value used to work on older Claude Code but current versions reject it
with: Path escapes plugin directory: ./ (skills). The error surfaces
on fresh /doctor runs even after v3.0.3 restored the archive contents.

Fix: omit the "skills" key entirely. Every other plugin in the Claude
Code marketplace ecosystem (compound-engineering, coding-tutor, codex,
esper, 15+ Anthropic official plugins) omits this key and the loader
auto-discovers skills/*/SKILL.md. Matching that pattern clears the
path-escape error on v2.1.109+ and remains compatible with older
Claude Code versions where the default-discovery path was already the
working code path.

Co-authored-by: Matt Van Horn <455140+mvanhorn@users.noreply.github.com>

.claude-plugin/marketplace.json

@@ -10,7 +10,7 @@
     {
       "name": "last30days",
       "description": "Research any topic across Reddit, X, YouTube, TikTok, Instagram, HN, Polymarket, GitHub, and 5+ more sources.",
-      "version": "3.0.3",
+      "version": "3.0.4",
       "author": {
         "name": "Matt Van Horn",
         "url": "https://github.com/mvanhorn"