feat: add AI data validation, test data generator, index advisor, and snapshots

Four new killer features leveraging AI (Ollama) and PostgreSQL internals:

- Data Validation: describe quality rules in natural language, AI generates
  SQL to find violations, run with pass/fail results and sample violations
- Test Data Generator: right-click table to generate realistic FK-aware test
  data with AI, preview before inserting in a transaction
- Index Advisor: analyze pg_stat tables + AI recommendations for CREATE/DROP
  INDEX with one-click apply
- Data Snapshots: export selected tables to JSON (FK-ordered), restore from
  file with optional truncate in a transaction

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/workspace/TabContent.tsx

@@ -6,6 +6,9 @@ import { RoleManagerView } from "@/components/management/RoleManagerView";
 import { SessionsView } from "@/components/management/SessionsView";
 import { EntityLookupPanel } from "@/components/lookup/EntityLookupPanel";
 import { ErdDiagram } from "@/components/erd/ErdDiagram";
+import { ValidationPanel } from "@/components/validation/ValidationPanel";
+import { IndexAdvisorPanel } from "@/components/index-advisor/IndexAdvisorPanel";
+import { SnapshotPanel } from "@/components/snapshots/SnapshotPanel";
 
 export function TabContent() {
   const { tabs, activeTabId, updateTab } = useAppStore();
@@ -81,6 +84,27 @@ export function TabContent() {
               />
             );
             break;
+          case "validation":
+            content = (
+              <ValidationPanel
+                connectionId={tab.connectionId}
+              />
+            );
+            break;
+          case "index-advisor":
+            content = (
+              <IndexAdvisorPanel
+                connectionId={tab.connectionId}
+              />
+            );
+            break;
+          case "snapshots":
+            content = (
+              <SnapshotPanel
+                connectionId={tab.connectionId}
+              />
+            );
+            break;
           default:
             content = null;
         }