fix: add missing plugin.json files and restore trailing newlines

- Add plugin.json for review-fix-a11y skill
- Add plugin.json for free-llm-api skill
- Restore POSIX-compliant trailing newlines in JSON index files

engineering-team/free-llm-api/plugin.json

@@ -0,0 +1,7 @@
+{
+  "name": "free-llm-api",
+  "version": "1.0.0",
+  "description": "Set up free or low-cost OpenAI-compatible LLM APIs: ChatAnywhere, Groq, Cerebras, OpenRouter, llm-mux, One API",
+  "author": "Alireza Rezvani",
+  "category": "engineering"
+}

engineering-team/review-fix-a11y/plugin.json

@@ -0,0 +1,7 @@
+{
+  "name": "review-fix-a11y",
+  "version": "1.0.0",
+  "description": "WCAG 2.2 accessibility audit and fix for React, Next.js, Vue, Angular, and HTML",
+  "author": "Neha",
+  "category": "engineering"
+}