fix(bi): add environment distribution breakdown to explain count discrepancies

Problem: Users noticed environment counts don't add up to total
- Total (All Environments): 868
- Development: 400
- Production: 300
- 400 + 300 = 700 ≠ 868

Root cause: Some audit logs have no environment field (null/undefined)
- These records ARE counted in "All Environments"
- These records are NOT counted when filtering by "Development" or "Production"

Solution:
- Added "Environment Distribution" section showing breakdown
- Displays: Development, Production, and Unspecified counts
- Shows warning when unspecified records exist
- Makes it clear why filtered totals may not match grand total

Technical details:
- Frontend filtering in audit-analytics.js
- Backend query uses: query.environment = environment (exact match only)
- Missing environment fields excluded from filtered results

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

public/admin/audit-analytics.html

@@ -151,6 +151,19 @@
       </div>
     </div>
 
+    <!-- Environment Distribution (shows why totals may not match filtered views) -->
+    <div id="environment-distribution" class="bg-white rounded-lg shadow-sm border border-gray-200 p-4 mb-6">
+      <h4 class="text-sm font-semibold text-gray-700 mb-3 flex items-center">
+        <svg class="w-4 h-4 mr-2 text-gray-600" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+          <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-6 0a1 1 0 001-1v-4a1 1 0 011-1h2a1 1 0 011 1v4a1 1 0 001 1m-6 0h6"/>
+        </svg>
+        Environment Distribution
+      </h4>
+      <div id="environment-stats" class="grid grid-cols-3 gap-3 text-sm">
+        <!-- Populated by JS -->
+      </div>
+    </div>
+
     <!-- Business Intelligence Section -->
     <div class="bg-gradient-to-r from-purple-50 to-blue-50 rounded-lg shadow-sm border-2 border-purple-200 p-6 mb-8">
       <div class="flex items-center justify-between mb-4">

public/js/admin/audit-analytics.js

@@ -138,6 +138,60 @@ function updateSummaryCards() {
 
   document.getElementById('violations-count').textContent = violationsCount;
   document.getElementById('services-count').textContent = servicesSet.size || 0;
+
+  // Environment distribution breakdown
+  updateEnvironmentDistribution();
+}
+
+// Update environment distribution display
+function updateEnvironmentDistribution() {
+  const environmentStats = {
+    development: 0,
+    production: 0,
+    unspecified: 0
+  };
+
+  auditData.forEach(d => {
+    if (d.environment === 'development') {
+      environmentStats.development++;
+    } else if (d.environment === 'production') {
+      environmentStats.production++;
+    } else {
+      environmentStats.unspecified++;
+    }
+  });
+
+  const total = auditData.length;
+  const statsEl = document.getElementById('environment-stats');
+
+  statsEl.innerHTML = `
+    <div class="text-center p-2 bg-blue-50 border border-blue-200 rounded">
+      <div class="font-semibold text-blue-700">Development</div>
+      <div class="text-2xl font-bold text-blue-900">${environmentStats.development}</div>
+      <div class="text-xs text-blue-600">${total > 0 ? ((environmentStats.development / total) * 100).toFixed(1) : 0}%</div>
+    </div>
+    <div class="text-center p-2 bg-green-50 border border-green-200 rounded">
+      <div class="font-semibold text-green-700">Production</div>
+      <div class="text-2xl font-bold text-green-900">${environmentStats.production}</div>
+      <div class="text-xs text-green-600">${total > 0 ? ((environmentStats.production / total) * 100).toFixed(1) : 0}%</div>
+    </div>
+    <div class="text-center p-2 bg-amber-50 border border-amber-200 rounded">
+      <div class="font-semibold text-amber-700">Unspecified</div>
+      <div class="text-2xl font-bold text-amber-900">${environmentStats.unspecified}</div>
+      <div class="text-xs text-amber-600">${total > 0 ? ((environmentStats.unspecified / total) * 100).toFixed(1) : 0}%</div>
+    </div>
+  `;
+
+  // Show warning if there are unspecified records
+  if (environmentStats.unspecified > 0) {
+    const warningHTML = `
+      <div class="col-span-3 mt-2 p-2 bg-amber-50 border border-amber-300 rounded text-xs text-amber-900">
+        <strong>⚠️ Note:</strong> ${environmentStats.unspecified} record(s) have no environment field.
+        These are included in "All Environments" but excluded when filtering by Development or Production.
+      </div>
+    `;
+    statsEl.innerHTML += warningHTML;
+  }
 }
 
 // Render Business Intelligence