Add base44 plugin

Official Base44 plugin — full-stack app development with CLI project management
and JavaScript/TypeScript SDK skills. MIT licensed, skills-only (no MCP server).

Partner escalation from #plugin-partner-escalations.
Already merged on -internal (PR #1466, 2026-04-07).

.claude-plugin/marketplace.json

@@ -169,6 +169,17 @@
       "category": "database",
       "homepage": "https://github.com/AzureCosmosDB/cosmosdb-claude-code-plugin"
     },
+    {
+      "name": "base44",
+      "description": "Build and deploy Base44 full-stack apps with CLI project management and JavaScript/TypeScript SDK development skills",
+      "category": "development",
+      "source": {
+        "source": "url",
+        "url": "https://github.com/base44/skills.git",
+        "sha": "c7039b37eca0e2916a565a7395040c00055bcf8b"
+      },
+      "homepage": "https://docs.base44.com"
+    },
     {
       "name": "box",
       "description": "Work with your Box content directly from Claude Code — search files, organize folders, collaborate with your team, and use Box AI to answer questions, summarize documents, and extract data without leaving your workflow.",