docs: harden public docs by removing security-sensitive details (#331)

* docs: remove security-sensitive implementation details from public documentation

Generalize or remove internal architecture details that could aid targeted
attacks — CVE tables, database schema, rate limit thresholds, proxy internals,
encryption algorithm names, and WebSocket middleware bypass info.

* test(metrics): fix flaky minute-bucket aggregation test

Floor baseTime to the start of the current minute so baseTime + 5000
never crosses a minute boundary and produces 2 buckets instead of 1.

backend/src/__tests__/database-metrics.test.ts

@@ -41,7 +41,7 @@ describe('DatabaseService - container metrics', () => {
   });
 
   it('aggregates metrics into minute buckets', () => {
-    const baseTime = Date.now();
+    const baseTime = Math.floor(Date.now() / 60000) * 60000; // floor to minute start
     // Insert two metrics within the same minute
     db.addContainerMetric({
       container_id: 'bucket-test',