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.

backend/src/catalog/effective-relationship-snapshot.ts

@@ -0,0 +1,93 @@
+import type { CatalogRelationship, CatalogRepository } from "./types.js";
+
+export interface EffectiveRelationshipSnapshotReader {
+  list(databaseId: string): Promise<CatalogRelationship[]>;
+}
+
+export interface EffectiveRelationshipSnapshotCoordinator {
+  run<T>(databaseId: string, operation: () => Promise<T>): Promise<T>;
+}
+
+export class EffectiveRelationshipSnapshotStaleError extends Error {}
+
+interface EffectiveRelationship {
+  sourceTable: string;
+  sourceColumns: string[];
+  targetTable: string;
+  targetColumns: string[];
+  origin: CatalogRelationship["origin"];
+}
+
+interface EffectiveRelationshipSnapshot {
+  schemaVersion: 1;
+  workspaceId: string;
+  relationships: EffectiveRelationship[];
+}
+
+const originRank: Record<CatalogRelationship["origin"], number> = {
+  physical: 0,
+  manual: 1,
+  generated: 2,
+};
+
+function endpointKey(relationship: EffectiveRelationship): string {
+  return [
+    relationship.sourceTable,
+    relationship.sourceColumns.join("\u0000"),
+    relationship.targetTable,
+    relationship.targetColumns.join("\u0000"),
+  ].join("\u0001");
+}
+
+function compareRelationships(left: EffectiveRelationship, right: EffectiveRelationship): number {
+  return endpointKey(left).localeCompare(endpointKey(right))
+    || originRank[left.origin] - originRank[right.origin];
+}
+
+/**
+ * Adapter from the mutable Catalog model to the immutable relationship contract consumed by the
+ * harness. The returned JSON is a deterministic projection, never an authored second store.
+ */
+export class EffectiveRelationshipSnapshotProvider {
+  constructor(
+    private readonly repository: Pick<CatalogRepository, "get" | "getByWorkspace">,
+    private readonly relationships: EffectiveRelationshipSnapshotReader,
+    private readonly operations: EffectiveRelationshipSnapshotCoordinator,
+  ) {}
+
+  async render(workspaceId: string): Promise<string | undefined> {
+    const database = await this.repository.getByWorkspace(workspaceId);
+    if (!database) return undefined;
+    return await this.operations.run(database.id, async () => {
+      const current = await this.repository.get(database.id);
+      if (!current || current.schemaSyncedVersion !== current.version) {
+        throw new EffectiveRelationshipSnapshotStaleError(
+          "effective relationship snapshot requires a current full schema synchronization",
+        );
+      }
+      const projected = (await this.relationships.list(database.id))
+        .filter((relationship) => relationship.status === "active")
+        .map((relationship): EffectiveRelationship => ({
+          sourceTable: relationship.sourceTableName,
+          sourceColumns: relationship.columns.map((column) => column.sourceColumnName),
+          targetTable: relationship.targetTableName,
+          targetColumns: relationship.columns.map((column) => column.targetColumnName),
+          origin: relationship.origin,
+        }))
+        .sort(compareRelationships);
+
+      const seen = new Set<string>();
+      const snapshot: EffectiveRelationshipSnapshot = {
+        schemaVersion: 1,
+        workspaceId,
+        relationships: projected.filter((relationship) => {
+          const key = endpointKey(relationship);
+          if (seen.has(key)) return false;
+          seen.add(key);
+          return true;
+        }),
+      };
+      return `${JSON.stringify(snapshot, null, 2)}\n`;
+    });
+  }
+}