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/DatabaseColumns.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";
@@ -20,6 +20,7 @@ import {
 import type { DatabaseNavigationState } from "./model";
 import { FleetActionSelector, type FleetActionOption } from "./FleetActionSelector";
 import { FleetLedgerDrawer } from "./FleetLedgerShell";
+import { NO_METADATA_GENERATION_LLM_MODEL_MESSAGE } from "./MetadataGenerationModelSelector";
 
 interface Props {
   databaseId: string;
@@ -34,7 +35,6 @@ interface Props {
   bindingReady?: boolean;
   catalogOperationActive?: boolean;
   onCatalogMetricsChanged?: () => void | Promise<void>;
-  metadataModelControl?: ReactNode;
   presentation?: "legacy" | "fleet";
 }
 
@@ -99,7 +99,6 @@ export function DatabaseColumns({
   bindingReady = true,
   catalogOperationActive = false,
   onCatalogMetricsChanged,
-  metadataModelControl,
   presentation = "legacy",
 }: Props) {
   const queryClient = useQueryClient();
@@ -307,7 +306,7 @@ export function DatabaseColumns({
         : selectedIds.length === 0
           ? "Select at least one column."
           : !selectedMetadataModel
-            ? "Choose a metadata model first."
+            ? NO_METADATA_GENERATION_LLM_MODEL_MESSAGE
             : descriptionGenerationActive || catalogOperationActive
               ? "Wait for the active catalog operation to finish."
               : busy
@@ -341,7 +340,7 @@ export function DatabaseColumns({
         : selectedIds.length === 0
           ? "Select at least one column."
           : !selectedMetadataModel
-            ? "Choose a metadata model first."
+            ? NO_METADATA_GENERATION_LLM_MODEL_MESSAGE
             : descriptionGenerationActive || catalogOperationActive
               ? "Wait for the active catalog operation to finish."
               : busy
@@ -468,7 +467,6 @@ export function DatabaseColumns({
                 busyLabel={sensitiveAction === "suggest" ? "Suggesting…" : sensitiveAction === "save" ? "Saving…" : "Running…"}
                 onRun={runFleetAction}
                 onClear={clearSelection}
-                renderContext={(action) => action === "generate-descriptions" || action === "suggest-sensitive" ? metadataModelControl : null}
                 label="Column action"
               />
             </>
@@ -501,7 +499,6 @@ export function DatabaseColumns({
                 busyLabel={sensitiveAction === "save" ? "Saving…" : "Running…"}
                 onRun={runFleetAction}
                 onClear={clearSelection}
-                renderContext={(action) => action === "generate-descriptions" || action === "suggest-sensitive" ? metadataModelControl : null}
                 label="Column action"
               />
               <input 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 columns" placeholder="Search" value={search} onChange={(event) => setSearch(event.target.value)} />