feat: add zCode Swarm — multi-agent orchestration system

- 6 agent skills: code-review, performance, security, architecture, test, git
- 4 coordinator modes: hierarchical, mesh, gossip, consensus
- Federated memory system (6 namespaces)
- Neural network agent recommendation
- Agent marketplace (plugin discovery/install)
- Real-time dashboard + performance metrics
- CRDT-based sync for decentralized modes
- 22 files, ~1400 lines total

Inspired by ruflo distributed multi-agent patterns.

quick-start.cjs

@@ -0,0 +1,34 @@
+#!/usr/bin/env node
+/**
+ * zCode Swarm - Quick Start
+ */
+
+const SwarmOrchestrator = require('./.zcode/agents/orchestrator.cjs');
+
+async function main() {
+  const orchestrator = new SwarmOrchestrator();
+
+  try {
+    await orchestrator.initialize();
+
+    // Demo: coordinate a code review task
+    const result = await orchestrator.coordinate({
+      type: 'code-review-swarm',
+      prId: 123,
+      diff: '// sample diff'
+    });
+
+    console.log('\n📊 Result:', JSON.stringify(result, null, 2));
+
+    // Status check
+    const status = orchestrator.getStatus();
+    console.log('\n🟢 Status:', JSON.stringify(status, null, 2));
+
+    await orchestrator.shutdown();
+  } catch (err) {
+    console.error('❌ Error:', err.message);
+    process.exit(1);
+  }
+}
+
+main();