Add external plugin agent-council (#2087)

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

.github/plugin/marketplace.json

@@ -16,6 +16,33 @@
       "description": "Drive Microsoft AgentRC from Copilot chat: assess AI readiness, generate Copilot instructions (flat or nested with applyTo globs for monorepos), and manage policies. Produces a self-contained static HTML dashboard at reports/index.html.",
       "version": "1.0.0"
     },
+    {
+      "name": "agent-council",
+      "description": "A runtime-portable 5-agent quality gate that adjudicates text artifacts before they ship. Five role-conditioned LLM deliberators run a 2-round async protocol with cross-read rebuttal and return one verdict — SHIP, REVISE, or HOLD — plus a structured revision brief and a full audit transcript.",
+      "version": "0.1.3",
+      "author": {
+        "name": "Parth Sangani",
+        "url": "https://github.com/Avyayalaya"
+      },
+      "repository": "https://github.com/Avyayalaya/agent-council",
+      "license": "MIT",
+      "keywords": [
+        "quality-gate",
+        "multi-agent",
+        "adjudication",
+        "council",
+        "llm-as-judge",
+        "agent-orchestration",
+        "review",
+        "claude-code",
+        "mcp"
+      ],
+      "source": {
+        "source": "github",
+        "repo": "Avyayalaya/agent-council",
+        "ref": "v0.1.3"
+      }
+    },
     {
       "name": "ai-ready",
       "description": "Analyze any repository and generate AI-ready configuration — AGENTS.md, copilot-instructions.md, CI workflows, issue templates, and more. Mines your PR review patterns and creates files customized to your stack.",