feat: consolidate database management work

Add catalog-owned logical relationships and runtime snapshots, extend the database-management UI and validation coverage, and document the updated operational workflow.

Keep active sensitive-generation status in a tooltip and indicator, and update the layout E2E to follow the history action in its new database-scoped location.

frontend/src/shell/database-management/DatabaseTables.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useMemo, useRef, useState, type ReactNode } from "react";
+import { useEffect, useMemo, useRef, useState } from "react";
 import { Menu } from "@base-ui/react/menu";
 import { useQuery, useQueryClient } from "@tanstack/react-query";
 import { AgGridReact } from "ag-grid-react";
@@ -25,6 +25,7 @@ import type { DatabaseNavigationState } from "./model";
 import { DatabaseColumns } from "./DatabaseColumns";
 import { FleetActionSelector, type FleetActionOption } from "./FleetActionSelector";
 import { FleetLedgerDrawer } from "./FleetLedgerShell";
+import { NO_METADATA_GENERATION_LLM_MODEL_MESSAGE } from "./MetadataGenerationModelSelector";
 
 interface Props {
   database: CatalogDatabase;
@@ -39,10 +40,11 @@ interface Props {
   onNestedNavigationChange?: (active: boolean) => void;
   onRunStarted: (run: CatalogSyncRun) => void;
   onOpenSync: () => void;
+  onOpenDescriptionHistory?: () => void;
+  onOpenSensitiveHistory?: () => void;
   onDescriptionGenerationRunStarted: (run: DescriptionGenerationRun) => void;
   onSuggestSensitive: (selection: SensitiveDataSuggestionRequest, scopeLabel: string) => Promise<void>;
   onCatalogMetricsChanged?: () => void | Promise<void>;
-  metadataModelControl?: ReactNode;
   presentation?: "legacy" | "fleet";
 }
 
@@ -93,10 +95,11 @@ export function DatabaseTables({
   onNestedNavigationChange,
   onRunStarted,
   onOpenSync,
+  onOpenDescriptionHistory,
+  onOpenSensitiveHistory,
   onDescriptionGenerationRunStarted,
   onSuggestSensitive,
   onCatalogMetricsChanged,
-  metadataModelControl,
   presentation = "legacy",
 }: Props) {
   const databaseId = database.id!;
@@ -314,7 +317,7 @@ export function DatabaseTables({
         : selectedIds.length === 0
           ? "Select at least one table."
           : !selectedMetadataModel
-            ? "Choose a metadata model first."
+            ? NO_METADATA_GENERATION_LLM_MODEL_MESSAGE
             : descriptionGenerationActive || Boolean(currentRun)
               ? "Wait for the active catalog operation to finish."
               : busy !== null
@@ -377,7 +380,7 @@ export function DatabaseTables({
         : selectedIds.length === 0
           ? "Select at least one table."
           : !selectedMetadataModel
-            ? "Choose a metadata model first."
+            ? NO_METADATA_GENERATION_LLM_MODEL_MESSAGE
             : descriptionGenerationActive || Boolean(currentRun)
               ? "Wait for the active catalog operation to finish."
               : busy !== null
@@ -487,8 +490,9 @@ export function DatabaseTables({
           <div className="flex min-h-12 flex-wrap items-center gap-3 border-b border-border bg-muted/25 px-3 py-2">
             <Button
               type="button"
-              variant="outline"
-              className="thot-fleet-icon-action border-primary/35 bg-primary/8 shadow-sm"
+              variant="ghost"
+              size="sm"
+              className="thot-fleet-icon-action thot-fleet-back-action"
               disabled={navigationBusy}
               data-tooltip="Tables"
               aria-label="Back to tables"
@@ -514,7 +518,6 @@ export function DatabaseTables({
             bindingReady={bindingReady}
             catalogOperationActive={Boolean(currentRun)}
             onCatalogMetricsChanged={onCatalogMetricsChanged}
-            metadataModelControl={metadataModelControl}
             presentation="fleet"
           />
         </section>
@@ -712,7 +715,6 @@ export function DatabaseTables({
                     selectRef={fleetActionSelectRef}
                     onRun={runFleetAction}
                     onClear={clearSelection}
-                    renderContext={(action) => action === "generate-descriptions" || action === "suggest-sensitive" ? metadataModelControl : null}
                     label="Table action"
                   />
                 </>
@@ -751,7 +753,6 @@ export function DatabaseTables({
                   selectRef={fleetActionSelectRef}
                   onRun={runFleetAction}
                   onClear={clearSelection}
-                  renderContext={(action) => action === "generate-descriptions" || action === "suggest-sensitive" ? metadataModelControl : null}
                   label="Table action"
                 />
                 <input ref={searchInputRef} className="h-8 min-w-40 flex-1 rounded-md border border-input bg-background px-2.5 text-sm outline-none focus:border-primary/60 focus:ring-3 focus:ring-ring/15" aria-label="Search tables" placeholder="Search" value={search} onChange={(event) => setSearch(event.target.value)} />
@@ -773,6 +774,8 @@ export function DatabaseTables({
               {currentRun ? <RefreshCw className="animate-spin" aria-hidden="true" /> : <History aria-hidden="true" />} Sync history
             </Button>
           ) : null}
+          {onOpenDescriptionHistory ? <Button type="button" size="sm" variant="outline" onClick={onOpenDescriptionHistory}><History aria-hidden="true" /> Description history</Button> : null}
+          {onOpenSensitiveHistory ? <Button type="button" size="sm" variant="outline" onClick={onOpenSensitiveHistory}><History aria-hidden="true" /> Sensitive history</Button> : null}
         </div>
         {!bindingReady ? <div className="border-b border-border bg-muted/35 px-4 py-3 text-sm text-muted-foreground">Test the current database binding from Overview before synchronizing tables.</div> : null}
         {fleetQueryError ?? <div className="relative min-h-[280px] flex-1">