Initial Auto-Build plugin structure

.claude-plugin/marketplace.json

@@ -0,0 +1,18 @@
+{
+  "name": "roa2web-tools",
+  "owner": {
+    "name": "ROA2WEB Team"
+  },
+  "metadata": {
+    "description": "Auto-Build plugin for spec-driven development workflows"
+  },
+  "plugins": [
+    {
+      "name": "auto-build",
+      "source": "./plugin",
+      "description": "Spec-driven build orchestration with git worktree isolation and session memory",
+      "version": "1.0.0",
+      "keywords": ["build", "spec", "automation", "worktree", "qa"]
+    }
+  ]
+}