Persist project settings updates

AGENTS.md

@@ -262,6 +262,9 @@ that have remained unchanged. ProjectDevice create, update, delete and
 global-to-project copy API/UI paths use these persistent commands and track the
 returned project revision. ProjectDevice synchronization/disconnect API and UI
 paths do the same; their undo action uses the project-wide history endpoint.
+Project voltage settings use the persistent `project.update-settings` command.
+Both voltage defaults change in one revision and Undo/Redo restores them
+together; the project PUT route requires `expectedRevision`.
 
 Required operations:
 

docs/circuit-list-editor-api.md

@@ -62,7 +62,8 @@ The public dispatcher currently supports `circuit.update`, `circuit.insert`,
 `circuit.reorder-section`, `circuit.reorder-sections`,
 `circuit.renumber-section` and
 `project-device.update`, `project-device.insert`, `project-device.delete` and
-`project-device.sync-rows`, all with schema version `1`. Other command types
+`project-device.sync-rows` as well as `project.update-settings`, all with
+schema version `1`. Other command types
 are rejected. Insert commands contain the complete entity or circuit block
 with stable ids; delete commands include the expected parent identity. Circuit
 snapshots contain zero, one or multiple complete device rows. Move commands
@@ -136,6 +137,18 @@ These write endpoints execute the typed `project-device.update`,
 returns `409 PROJECT_REVISION_CONFLICT`. Updating a project device still never
 synchronizes linked circuit rows implicitly.
 
+### Project Settings
+
+- `PUT /projects/:projectId`
+  - request:
+    `{ "expectedRevision": 12, "singlePhaseVoltageV": 230, "threePhaseVoltageV": 400 }`
+  - executes `project.update-settings` as one atomic revision
+  - response:
+    `{ "project": { ... }, "revision": { ... }, "history": { ... } }`
+  - persistent Undo/Redo restores both voltage values together
+  - unchanged values are rejected without creating a revision; a stale
+    revision returns `409 PROJECT_REVISION_CONFLICT`
+
 Example:
 
 ```json

docs/current-architecture.md

@@ -175,6 +175,12 @@ unverknüpft und vollständig unverändert sind. Gerät, Linkänderungen, Revisi
 und Historienstapel teilen dieselbe Transaktion. Create, Import aus der globalen
 Gerätebibliothek und Delete laufen über dieselbe Command-Grenze; ihre Antworten
 liefern Gerät und aktualisierten Historienstand an die Projektseite zurück.
+`project.update-settings` versioniert die beiden Projekt-Standardspannungen als
+eine atomare Änderung. Der Store leitet das inverse Kommando aus dem
+gespeicherten Projekt ab und schreibt Werte, Revision und Historienstapel
+gemeinsam. `PUT /api/projects/:projectId` verlangt deshalb
+`expectedRevision`, liefert Projekt plus aktualisierten Historienstand und
+besitzt keinen separaten direkten Settings-Schreibweg mehr.
 
 ## Projektgeräte
 

docs/project-history-and-external-model-architecture.md

@@ -252,6 +252,9 @@ Completed foundation:
 - `project-device.insert` and `project-device.delete` preserve stable device
   ids; delete undo restores links only from complete unchanged disconnected-row
   snapshots in the same transaction
+- `project.update-settings` persists both project voltage defaults, its exact
+  inverse, revision and history transition atomically; the project page and
+  existing PUT route require the current expected revision
 
 Remaining constraints before completing project version history:
 

docs/spec/07-implementation-phases-todo.md

@@ -438,6 +438,9 @@ Implemented foundation:
 - ProjectDevice synchronization and disconnect endpoints also require
   `expectedRevision`; their UI undo uses project-wide persistent history and
   the obsolete direct restore/reconnect write paths are removed
+- project voltage settings use `project.update-settings`; both values, inverse,
+  revision and history transition commit atomically and the former direct
+  settings write is removed
 - revision metadata, change-set payloads and the project counter are committed
   in one SQLite transaction
 - a stale expected revision produces no history writes

package.json

@@ -14,8 +14,8 @@
     "build:api": "tsc -p tsconfig.json",
     "build:web": "next build",
     "start": "node dist/server/index.js",
-    "test": "tsx --test tests/project-device-schema.test.ts tests/project-device-schema-migration.test.ts tests/project-device-placement.service.test.ts tests/project-device-sync.service.test.ts tests/legacy-consumer-migration-planner.test.ts tests/legacy-consumer-migration.repository.test.ts tests/circuit-numbering.service.test.ts tests/circuit-power-calculation.test.ts tests/circuit-tree.controller.test.ts tests/circuit-editor-history.test.ts tests/circuit-grid-insertion.test.ts tests/circuit-grid-safety.test.ts tests/circuit-grid-model.test.ts tests/circuit-structure-command.test.ts tests/circuit-device-row-move-command.test.ts tests/circuit-section-reorder-command.test.ts tests/circuit-section-renumber-command.test.ts tests/circuit-grid-projection.test.ts tests/distribution-board.repository.test.ts tests/project-device-project-command.repository.test.ts tests/project-device-structure-project-command.repository.test.ts tests/project-device-row-sync-project-command.repository.test.ts tests/circuit-section-reorder-project-command.repository.test.ts tests/circuit-section-renumber-project-command.repository.test.ts tests/project-command.model.test.ts tests/project-revision.repository.test.ts tests/circuit-project-command.repository.test.ts tests/circuit-structure-project-command.repository.test.ts tests/circuit-device-row-project-command.repository.test.ts tests/circuit-device-row-structure-project-command.repository.test.ts tests/circuit-device-row-move-project-command.repository.test.ts tests/project-history.repository.test.ts tests/project-history-timeline.test.ts tests/project-version-history.test.ts tests/project-state-snapshot.test.ts tests/project-snapshot.repository.test.ts tests/project-state-restore-command.repository.test.ts tests/project-command.service.test.ts tests/database-backup.test.ts",
-    "test:watch": "tsx --watch --test tests/project-device-schema.test.ts tests/project-device-schema-migration.test.ts tests/project-device-placement.service.test.ts tests/project-device-sync.service.test.ts tests/legacy-consumer-migration-planner.test.ts tests/legacy-consumer-migration.repository.test.ts tests/circuit-numbering.service.test.ts tests/circuit-power-calculation.test.ts tests/circuit-tree.controller.test.ts tests/circuit-editor-history.test.ts tests/circuit-grid-insertion.test.ts tests/circuit-grid-safety.test.ts tests/circuit-grid-model.test.ts tests/circuit-structure-command.test.ts tests/circuit-device-row-move-command.test.ts tests/circuit-section-reorder-command.test.ts tests/circuit-section-renumber-command.test.ts tests/circuit-grid-projection.test.ts tests/distribution-board.repository.test.ts tests/project-device-project-command.repository.test.ts tests/project-device-structure-project-command.repository.test.ts tests/project-device-row-sync-project-command.repository.test.ts tests/circuit-section-reorder-project-command.repository.test.ts tests/circuit-section-renumber-project-command.repository.test.ts tests/project-command.model.test.ts tests/project-revision.repository.test.ts tests/circuit-project-command.repository.test.ts tests/circuit-structure-project-command.repository.test.ts tests/circuit-device-row-project-command.repository.test.ts tests/circuit-device-row-structure-project-command.repository.test.ts tests/circuit-device-row-move-project-command.repository.test.ts tests/project-history.repository.test.ts tests/project-history-timeline.test.ts tests/project-version-history.test.ts tests/project-state-snapshot.test.ts tests/project-snapshot.repository.test.ts tests/project-state-restore-command.repository.test.ts tests/project-command.service.test.ts tests/database-backup.test.ts",
+    "test": "tsx --test tests/project-device-schema.test.ts tests/project-device-schema-migration.test.ts tests/project-device-placement.service.test.ts tests/project-device-sync.service.test.ts tests/legacy-consumer-migration-planner.test.ts tests/legacy-consumer-migration.repository.test.ts tests/circuit-numbering.service.test.ts tests/circuit-power-calculation.test.ts tests/circuit-tree.controller.test.ts tests/circuit-editor-history.test.ts tests/circuit-grid-insertion.test.ts tests/circuit-grid-safety.test.ts tests/circuit-grid-model.test.ts tests/circuit-structure-command.test.ts tests/circuit-device-row-move-command.test.ts tests/circuit-section-reorder-command.test.ts tests/circuit-section-renumber-command.test.ts tests/circuit-grid-projection.test.ts tests/distribution-board.repository.test.ts tests/project-device-project-command.repository.test.ts tests/project-device-structure-project-command.repository.test.ts tests/project-device-row-sync-project-command.repository.test.ts tests/circuit-section-reorder-project-command.repository.test.ts tests/circuit-section-renumber-project-command.repository.test.ts tests/project-command.model.test.ts tests/project-revision.repository.test.ts tests/circuit-project-command.repository.test.ts tests/circuit-structure-project-command.repository.test.ts tests/circuit-device-row-project-command.repository.test.ts tests/circuit-device-row-structure-project-command.repository.test.ts tests/circuit-device-row-move-project-command.repository.test.ts tests/project-history.repository.test.ts tests/project-history-timeline.test.ts tests/project-version-history.test.ts tests/project-settings-project-command.repository.test.ts tests/project-state-snapshot.test.ts tests/project-snapshot.repository.test.ts tests/project-state-restore-command.repository.test.ts tests/project-command.service.test.ts tests/database-backup.test.ts",
+    "test:watch": "tsx --watch --test tests/project-device-schema.test.ts tests/project-device-schema-migration.test.ts tests/project-device-placement.service.test.ts tests/project-device-sync.service.test.ts tests/legacy-consumer-migration-planner.test.ts tests/legacy-consumer-migration.repository.test.ts tests/circuit-numbering.service.test.ts tests/circuit-power-calculation.test.ts tests/circuit-tree.controller.test.ts tests/circuit-editor-history.test.ts tests/circuit-grid-insertion.test.ts tests/circuit-grid-safety.test.ts tests/circuit-grid-model.test.ts tests/circuit-structure-command.test.ts tests/circuit-device-row-move-command.test.ts tests/circuit-section-reorder-command.test.ts tests/circuit-section-renumber-command.test.ts tests/circuit-grid-projection.test.ts tests/distribution-board.repository.test.ts tests/project-device-project-command.repository.test.ts tests/project-device-structure-project-command.repository.test.ts tests/project-device-row-sync-project-command.repository.test.ts tests/circuit-section-reorder-project-command.repository.test.ts tests/circuit-section-renumber-project-command.repository.test.ts tests/project-command.model.test.ts tests/project-revision.repository.test.ts tests/circuit-project-command.repository.test.ts tests/circuit-structure-project-command.repository.test.ts tests/circuit-device-row-project-command.repository.test.ts tests/circuit-device-row-structure-project-command.repository.test.ts tests/circuit-device-row-move-project-command.repository.test.ts tests/project-history.repository.test.ts tests/project-history-timeline.test.ts tests/project-version-history.test.ts tests/project-settings-project-command.repository.test.ts tests/project-state-snapshot.test.ts tests/project-snapshot.repository.test.ts tests/project-state-restore-command.repository.test.ts tests/project-command.service.test.ts tests/database-backup.test.ts",
     "db:generate": "drizzle-kit generate",
     "db:migrate": "drizzle-kit migrate",
     "db:backup": "tsx scripts/db-backup.ts",

src/app/projects/[projectId]/page.tsx

@@ -245,17 +245,21 @@ export default function ProjectDetailPage() {
   }
 
   async function handleSaveProjectSettings() {
-    if (!projectId) {
+    if (!projectId || !project) {
       return;
     }
     setIsSaving(true);
     setError(null);
     try {
-      const updated = await updateProjectSettings(projectId, {
-        singlePhaseVoltageV: Number(singlePhaseVoltageV),
-        threePhaseVoltageV: Number(threePhaseVoltageV),
-      });
-      setProject(updated);
+      const result = await updateProjectSettings(
+        projectId,
+        project.currentRevision,
+        {
+          singlePhaseVoltageV: Number(singlePhaseVoltageV),
+          threePhaseVoltageV: Number(threePhaseVoltageV),
+        }
+      );
+      setProject(result.project);
     } catch (err) {
       setError(err instanceof Error ? err.message : "Projekteigenschaften konnten nicht gespeichert werden.");
     } finally {
@@ -599,7 +603,14 @@ export default function ProjectDetailPage() {
                     className="btn btn-primary w-100"
                     type="button"
                     onClick={handleSaveProjectSettings}
-                    disabled={isSaving}
+                    disabled={
+                      isSaving ||
+                      !project ||
+                      (Number(singlePhaseVoltageV) ===
+                        project.singlePhaseVoltageV &&
+                        Number(threePhaseVoltageV) ===
+                          project.threePhaseVoltageV)
+                    }
                   >
                     Projekteigenschaften speichern
                   </button>

src/db/repositories/project-settings-project-command.repository.ts

@@ -0,0 +1,71 @@
+import { eq } from "drizzle-orm";
+import {
+  assertProjectSettingsUpdateProjectCommand,
+  createProjectSettingsUpdateProjectCommand,
+} from "../../domain/models/project-settings-project-command.model.js";
+import type {
+  ExecuteProjectSettingsUpdateCommandInput,
+  ProjectSettingsProjectCommandStore,
+} from "../../domain/ports/project-settings-project-command.store.js";
+import type { AppDatabase } from "../database-context.js";
+import { projects } from "../schema/projects.js";
+import { applyProjectHistoryTransition } from "./project-history.persistence.js";
+import { appendProjectRevision } from "./project-revision.persistence.js";
+
+export class ProjectSettingsProjectCommandRepository
+  implements ProjectSettingsProjectCommandStore
+{
+  constructor(private readonly database: AppDatabase) {}
+
+  executeUpdate(input: ExecuteProjectSettingsUpdateCommandInput) {
+    assertProjectSettingsUpdateProjectCommand(input.command);
+    return this.database.transaction((tx) => {
+      const current = tx
+        .select()
+        .from(projects)
+        .where(eq(projects.id, input.projectId))
+        .get();
+      if (!current) {
+        throw new Error("Project not found.");
+      }
+      if (
+        current.singlePhaseVoltageV ===
+          input.command.payload.singlePhaseVoltageV &&
+        current.threePhaseVoltageV ===
+          input.command.payload.threePhaseVoltageV
+      ) {
+        throw new Error("Project settings did not change.");
+      }
+
+      const inverse = createProjectSettingsUpdateProjectCommand({
+        singlePhaseVoltageV: current.singlePhaseVoltageV,
+        threePhaseVoltageV: current.threePhaseVoltageV,
+      });
+      const updated = tx
+        .update(projects)
+        .set(input.command.payload)
+        .where(eq(projects.id, input.projectId))
+        .run();
+      if (updated.changes !== 1) {
+        throw new Error("Project changed before settings update.");
+      }
+
+      const revision = appendProjectRevision(tx, {
+        projectId: input.projectId,
+        expectedRevision: input.expectedRevision,
+        source: input.source,
+        description: input.description,
+        actorId: input.actorId,
+        forward: input.command,
+        inverse,
+      });
+      applyProjectHistoryTransition(tx, {
+        projectId: input.projectId,
+        source: input.source,
+        recordedChangeSetId: revision.changeSetId,
+        targetChangeSetId: input.historyTargetChangeSetId,
+      });
+      return { revision, inverse };
+    });
+  }
+}

src/db/repositories/project.repository.ts

@@ -4,7 +4,6 @@ import { db } from "../client.js";
 import { projects } from "../schema/projects.js";
 import type {
   CreateProjectInput,
-  UpdateProjectSettingsInput,
 } from "../../shared/validation/project-structure.schemas.js";
 
 export class ProjectRepository {
@@ -30,16 +29,6 @@ export class ProjectRepository {
     return row ?? null;
   }
 
-  async updateSettings(projectId: string, input: UpdateProjectSettingsInput) {
-    await db
-      .update(projects)
-      .set({
-        singlePhaseVoltageV: input.singlePhaseVoltageV,
-        threePhaseVoltageV: input.threePhaseVoltageV,
-      })
-      .where(eq(projects.id, projectId));
-  }
-
   async delete(projectId: string) {
     await db.delete(projects).where(eq(projects.id, projectId));
   }

src/domain/models/project-settings-project-command.model.ts

@@ -0,0 +1,61 @@
+import type { SerializedProjectCommand } from "./project-command.model.js";
+
+export const projectSettingsUpdateCommandType =
+  "project.update-settings" as const;
+export const projectSettingsUpdateCommandSchemaVersion = 1 as const;
+
+export interface ProjectSettingsValues {
+  singlePhaseVoltageV: number;
+  threePhaseVoltageV: number;
+}
+
+export interface ProjectSettingsUpdateProjectCommand
+  extends SerializedProjectCommand<ProjectSettingsValues> {
+  schemaVersion: typeof projectSettingsUpdateCommandSchemaVersion;
+  type: typeof projectSettingsUpdateCommandType;
+}
+
+export function createProjectSettingsUpdateProjectCommand(
+  values: ProjectSettingsValues
+): ProjectSettingsUpdateProjectCommand {
+  const command: ProjectSettingsUpdateProjectCommand = {
+    schemaVersion: projectSettingsUpdateCommandSchemaVersion,
+    type: projectSettingsUpdateCommandType,
+    payload: { ...values },
+  };
+  assertProjectSettingsUpdateProjectCommand(command);
+  return command;
+}
+
+export function assertProjectSettingsUpdateProjectCommand(
+  command: SerializedProjectCommand<unknown>
+): asserts command is ProjectSettingsUpdateProjectCommand {
+  if (
+    command.schemaVersion !== projectSettingsUpdateCommandSchemaVersion ||
+    command.type !== projectSettingsUpdateCommandType
+  ) {
+    throw new Error("Unsupported project settings update command.");
+  }
+  if (
+    !isPlainObject(command.payload) ||
+    !isPositiveFiniteNumber(command.payload.singlePhaseVoltageV) ||
+    !isPositiveFiniteNumber(command.payload.threePhaseVoltageV) ||
+    Object.keys(command.payload).length !== 2
+  ) {
+    throw new Error(
+      "Project settings update command contains invalid voltages."
+    );
+  }
+}
+
+function isPositiveFiniteNumber(value: unknown): value is number {
+  return (
+    typeof value === "number" &&
+    Number.isFinite(value) &&
+    value > 0
+  );
+}
+
+function isPlainObject(value: unknown): value is Record<string, unknown> {
+  return value !== null && typeof value === "object" && !Array.isArray(value);
+}

src/domain/ports/project-settings-project-command.store.ts

@@ -0,0 +1,26 @@
+import type { ProjectSettingsUpdateProjectCommand } from "../models/project-settings-project-command.model.js";
+import type {
+  AppendedProjectRevision,
+  ProjectRevisionSource,
+} from "./project-revision.store.js";
+
+export interface ExecuteProjectSettingsUpdateCommandInput {
+  projectId: string;
+  expectedRevision: number;
+  source: ProjectRevisionSource;
+  description?: string;
+  actorId?: string;
+  historyTargetChangeSetId?: string;
+  command: ProjectSettingsUpdateProjectCommand;
+}
+
+export interface ExecutedProjectSettingsUpdateCommand {
+  revision: AppendedProjectRevision;
+  inverse: ProjectSettingsUpdateProjectCommand;
+}
+
+export interface ProjectSettingsProjectCommandStore {
+  executeUpdate(
+    input: ExecuteProjectSettingsUpdateCommandInput
+  ): ExecutedProjectSettingsUpdateCommand;
+}

src/domain/services/project-command.service.ts

@@ -45,6 +45,10 @@ import {
   assertProjectStateRestoreCommand,
   projectStateRestoreCommandType,
 } from "../models/project-state-restore-command.model.js";
+import {
+  assertProjectSettingsUpdateProjectCommand,
+  projectSettingsUpdateCommandType,
+} from "../models/project-settings-project-command.model.js";
 import {
   assertProjectDeviceRowSyncProjectCommand,
   projectDeviceRowSyncCommandType,
@@ -80,6 +84,7 @@ import type { ProjectDeviceProjectCommandStore } from "../ports/project-device-p
 import type { ProjectDeviceRowSyncProjectCommandStore } from "../ports/project-device-row-sync-project-command.store.js";
 import type { ProjectDeviceStructureProjectCommandStore } from "../ports/project-device-structure-project-command.store.js";
 import type { ProjectRevisionSource } from "../ports/project-revision.store.js";
+import type { ProjectSettingsProjectCommandStore } from "../ports/project-settings-project-command.store.js";
 import type { ProjectStateRestoreCommandStore } from "../ports/project-state-restore-command.store.js";
 
 interface DispatchProjectCommandInput {
@@ -104,6 +109,7 @@ export class ProjectCommandService implements ProjectCommandExecutor {
     private readonly projectDeviceStructureStore: ProjectDeviceStructureProjectCommandStore,
     private readonly projectDeviceStore: ProjectDeviceProjectCommandStore,
     private readonly projectDeviceRowSyncStore: ProjectDeviceRowSyncProjectCommandStore,
+    private readonly projectSettingsStore: ProjectSettingsProjectCommandStore,
     private readonly projectStateRestoreStore: ProjectStateRestoreCommandStore,
     private readonly historyStore: ProjectHistoryStore
   ) {}
@@ -294,6 +300,13 @@ export class ProjectCommandService implements ProjectCommandExecutor {
           command: input.command,
         }).revision;
       }
+      case projectSettingsUpdateCommandType: {
+        assertProjectSettingsUpdateProjectCommand(input.command);
+        return this.projectSettingsStore.executeUpdate({
+          ...input,
+          command: input.command,
+        }).revision;
+      }
       case projectStateRestoreCommandType: {
         assertProjectStateRestoreCommand(input.command);
         return this.projectStateRestoreStore.execute({

src/frontend/types.ts

@@ -58,6 +58,11 @@ export interface ProjectSnapshotRestoreResultDto
   snapshot: ProjectSnapshotMetadataDto;
 }
 
+export interface ProjectSettingsCommandResultDto
+  extends ProjectCommandResultDto {
+  project: ProjectDto;
+}
+
 export interface ProjectCommandDto {
   schemaVersion: number;
   type: string;

src/frontend/utils/api.ts

@@ -15,6 +15,7 @@ import type {
   ProjectRevisionPageDto,
   ProjectSnapshotMetadataDto,
   ProjectSnapshotRestoreResultDto,
+  ProjectSettingsCommandResultDto,
   ProjectDeviceSyncCommandResultDto,
   ProjectDeviceSyncPreviewDto,
   ProjectDto,
@@ -205,12 +206,16 @@ export function createProject(name: string) {
 
 export function updateProjectSettings(
   projectId: string,
+  expectedRevision: number,
   input: { singlePhaseVoltageV: number; threePhaseVoltageV: number }
 ) {
-  return request<ProjectDto>(`/api/projects/${projectId}`, {
+  return request<ProjectSettingsCommandResultDto>(
+    `/api/projects/${projectId}`,
+    {
     method: "PUT",
-    body: JSON.stringify(input),
-  });
+      body: JSON.stringify({ expectedRevision, ...input }),
+    }
+  );
 }
 
 export function listDistributionBoards(projectId: string) {

src/frontend/utils/project-version-history.ts

@@ -28,6 +28,7 @@ const commandTypeLabels: Record<string, string> = {
   "project-device.insert": "Projektgerät angelegt",
   "project-device.delete": "Projektgerät gelöscht",
   "project-device.sync-rows": "Projektgerät-Verknüpfungen geändert",
+  "project.update-settings": "Projekteinstellungen bearbeitet",
   "project.restore-state": "Projektstand wiederhergestellt",
 };
 

src/server/composition/project-command-stores.ts

@@ -10,6 +10,7 @@ import { ProjectHistoryRepository } from "../../db/repositories/project-history.
 import { ProjectDeviceProjectCommandRepository } from "../../db/repositories/project-device-project-command.repository.js";
 import { ProjectDeviceRowSyncProjectCommandRepository } from "../../db/repositories/project-device-row-sync-project-command.repository.js";
 import { ProjectDeviceStructureProjectCommandRepository } from "../../db/repositories/project-device-structure-project-command.repository.js";
+import { ProjectSettingsProjectCommandRepository } from "../../db/repositories/project-settings-project-command.repository.js";
 import { ProjectStateRestoreCommandRepository } from "../../db/repositories/project-state-restore-command.repository.js";
 import { ProjectCommandService } from "../../domain/services/project-command.service.js";
 
@@ -32,6 +33,8 @@ export const projectDeviceProjectCommandStore =
   new ProjectDeviceProjectCommandRepository(db);
 export const projectDeviceRowSyncProjectCommandStore =
   new ProjectDeviceRowSyncProjectCommandRepository(db);
+export const projectSettingsProjectCommandStore =
+  new ProjectSettingsProjectCommandRepository(db);
 export const projectStateRestoreCommandStore =
   new ProjectStateRestoreCommandRepository(db);
 export const projectHistoryStore = new ProjectHistoryRepository(db);
@@ -46,6 +49,7 @@ export const projectCommandService = new ProjectCommandService(
   projectDeviceStructureProjectCommandStore,
   projectDeviceProjectCommandStore,
   projectDeviceRowSyncProjectCommandStore,
+  projectSettingsProjectCommandStore,
   projectStateRestoreCommandStore,
   projectHistoryStore
 );

src/server/controllers/project.controller.ts

@@ -4,6 +4,9 @@ import {
   createProjectSchema,
   updateProjectSettingsSchema,
 } from "../../shared/validation/project-structure.schemas.js";
+import { createProjectSettingsUpdateProjectCommand } from "../../domain/models/project-settings-project-command.model.js";
+import { projectCommandService } from "../composition/project-command-stores.js";
+import { respondWithProjectCommandError } from "./project-command.controller.js";
 
 const projectRepository = new ProjectRepository();
 
@@ -44,10 +47,20 @@ export async function updateProjectSettings(req: Request, res: Response) {
     return res.status(400).json({ error: parsed.error.flatten() });
   }
 
-  await projectRepository.updateSettings(projectId, parsed.data);
-  const row = await projectRepository.findById(projectId);
-  if (!row) {
-    return res.status(404).json({ error: "Project not found" });
+  const { expectedRevision, ...settings } = parsed.data;
+  try {
+    const result = projectCommandService.executeUser({
+      projectId,
+      expectedRevision,
+      description: "Projekteinstellungen bearbeiten",
+      command: createProjectSettingsUpdateProjectCommand(settings),
+    });
+    const project = await projectRepository.findById(projectId);
+    if (!project) {
+      throw new Error("Updated project could not be loaded.");
+    }
+    return res.json({ ...result, project });
+  } catch (error) {
+    return respondWithProjectCommandError(error, res);
   }
-  return res.json(row);
 }

src/shared/validation/project-structure.schemas.ts

@@ -1,4 +1,5 @@
 import { z } from "zod";
+import { expectedProjectRevisionSchema } from "./project-command.schemas.js";
 
 export const createProjectSchema = z.object({
   name: z.string().min(1),
@@ -6,10 +7,13 @@ export const createProjectSchema = z.object({
   threePhaseVoltageV: z.number().positive().optional(),
 });
 
-export const updateProjectSettingsSchema = z.object({
-  singlePhaseVoltageV: z.number().positive(),
-  threePhaseVoltageV: z.number().positive(),
-});
+export const updateProjectSettingsSchema = z
+  .object({
+    expectedRevision: expectedProjectRevisionSchema,
+    singlePhaseVoltageV: z.number().positive(),
+    threePhaseVoltageV: z.number().positive(),
+  })
+  .strict();
 
 export const createDistributionBoardSchema = z.object({
   name: z.string().min(1),

tests/project-command.service.test.ts

@@ -20,6 +20,7 @@ import { ProjectDeviceProjectCommandRepository } from "../src/db/repositories/pr
 import { ProjectDeviceRowSyncProjectCommandRepository } from "../src/db/repositories/project-device-row-sync-project-command.repository.js";
 import { ProjectDeviceStructureProjectCommandRepository } from "../src/db/repositories/project-device-structure-project-command.repository.js";
 import { ProjectStateRestoreCommandRepository } from "../src/db/repositories/project-state-restore-command.repository.js";
+import { ProjectSettingsProjectCommandRepository } from "../src/db/repositories/project-settings-project-command.repository.js";
 import { circuitDeviceRows } from "../src/db/schema/circuit-device-rows.js";
 import { circuitSections } from "../src/db/schema/circuit-sections.js";
 import { circuits } from "../src/db/schema/circuits.js";
@@ -43,6 +44,7 @@ import { createCircuitInsertProjectCommand } from "../src/domain/models/circuit-
 import { createProjectDeviceRowSyncProjectCommand } from "../src/domain/models/project-device-row-sync-project-command.model.js";
 import { createProjectDeviceUpdateProjectCommand } from "../src/domain/models/project-device-project-command.model.js";
 import { createProjectDeviceInsertProjectCommand } from "../src/domain/models/project-device-structure-project-command.model.js";
+import { createProjectSettingsUpdateProjectCommand } from "../src/domain/models/project-settings-project-command.model.js";
 import { ProjectCommandService } from "../src/domain/services/project-command.service.js";
 
 function createTestDatabase(): DatabaseContext {
@@ -102,6 +104,7 @@ function createService(context: DatabaseContext) {
     new ProjectDeviceStructureProjectCommandRepository(context.db),
     new ProjectDeviceProjectCommandRepository(context.db),
     new ProjectDeviceRowSyncProjectCommandRepository(context.db),
+    new ProjectSettingsProjectCommandRepository(context.db),
     new ProjectStateRestoreCommandRepository(context.db),
     new ProjectHistoryRepository(context.db)
   );
@@ -924,6 +927,58 @@ describe("project command service", () => {
     }
   });
 
+  it("dispatches project settings updates through persistent history", () => {
+    const context = createTestDatabase();
+    try {
+      const service = createService(context);
+      const updated = service.executeUser({
+        projectId: "project-1",
+        expectedRevision: 0,
+        command: createProjectSettingsUpdateProjectCommand({
+          singlePhaseVoltageV: 240,
+          threePhaseVoltageV: 415,
+        }),
+      });
+      assert.equal(updated.history.currentRevision, 1);
+      assert.deepEqual(
+        context.db
+          .select({
+            singlePhaseVoltageV: projects.singlePhaseVoltageV,
+            threePhaseVoltageV: projects.threePhaseVoltageV,
+          })
+          .from(projects)
+          .where(eq(projects.id, "project-1"))
+          .get(),
+        {
+          singlePhaseVoltageV: 240,
+          threePhaseVoltageV: 415,
+        }
+      );
+
+      const undone = service.undo({
+        projectId: "project-1",
+        expectedRevision: 1,
+      });
+      assert.equal(undone.history.currentRevision, 2);
+      assert.deepEqual(
+        context.db
+          .select({
+            singlePhaseVoltageV: projects.singlePhaseVoltageV,
+            threePhaseVoltageV: projects.threePhaseVoltageV,
+          })
+          .from(projects)
+          .where(eq(projects.id, "project-1"))
+          .get(),
+        {
+          singlePhaseVoltageV: 230,
+          threePhaseVoltageV: 400,
+        }
+      );
+    } finally {
+      context.close();
+    }
+  });
+
   it("rejects unsupported and malformed commands before domain writes", () => {
     const context = createTestDatabase();
     try {

tests/project-settings-project-command.repository.test.ts

@@ -0,0 +1,248 @@
+import path from "node:path";
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import { eq } from "drizzle-orm";
+import { migrate } from "drizzle-orm/better-sqlite3/migrator";
+import {
+  createDatabaseContext,
+  type DatabaseContext,
+} from "../src/db/database-context.js";
+import { ProjectHistoryRepository } from "../src/db/repositories/project-history.repository.js";
+import { ProjectSettingsProjectCommandRepository } from "../src/db/repositories/project-settings-project-command.repository.js";
+import { projectRevisions } from "../src/db/schema/project-revisions.js";
+import { projects } from "../src/db/schema/projects.js";
+import { ProjectRevisionConflictError } from "../src/domain/errors/project-revision-conflict.error.js";
+import { createProjectSettingsUpdateProjectCommand } from "../src/domain/models/project-settings-project-command.model.js";
+import { updateProjectSettings } from "../src/frontend/utils/api.js";
+
+function createTestDatabase(): DatabaseContext {
+  const context = createDatabaseContext(":memory:");
+  migrate(context.db, {
+    migrationsFolder: path.resolve("src", "db", "migrations"),
+  });
+  context.db
+    .insert(projects)
+    .values({
+      id: "project-1",
+      name: "Testprojekt",
+      singlePhaseVoltageV: 230,
+      threePhaseVoltageV: 400,
+    })
+    .run();
+  return context;
+}
+
+function getSettings(context: DatabaseContext) {
+  return context.db
+    .select({
+      singlePhaseVoltageV: projects.singlePhaseVoltageV,
+      threePhaseVoltageV: projects.threePhaseVoltageV,
+      currentRevision: projects.currentRevision,
+    })
+    .from(projects)
+    .where(eq(projects.id, "project-1"))
+    .get();
+}
+
+describe("project settings project-command repository", () => {
+  it("validates settings commands and sends the expected revision from the frontend", async () => {
+    assert.throws(
+      () =>
+        createProjectSettingsUpdateProjectCommand({
+          singlePhaseVoltageV: 0,
+          threePhaseVoltageV: 400,
+        }),
+      /invalid voltages/
+    );
+    const requests: Array<{ url: string; body: unknown }> = [];
+    const originalFetch = globalThis.fetch;
+    globalThis.fetch = async (input, init) => {
+      requests.push({
+        url: String(input),
+        body: JSON.parse(String(init?.body)),
+      });
+      return new Response(JSON.stringify({}), {
+        status: 200,
+        headers: { "Content-Type": "application/json" },
+      });
+    };
+    try {
+      await updateProjectSettings("project-1", 7, {
+        singlePhaseVoltageV: 240,
+        threePhaseVoltageV: 415,
+      });
+    } finally {
+      globalThis.fetch = originalFetch;
+    }
+    assert.deepEqual(requests, [
+      {
+        url: "/api/projects/project-1",
+        body: {
+          expectedRevision: 7,
+          singlePhaseVoltageV: 240,
+          threePhaseVoltageV: 415,
+        },
+      },
+    ]);
+  });
+
+  it("updates both voltages and supports persisted undo and redo", () => {
+    const context = createTestDatabase();
+    try {
+      const repository = new ProjectSettingsProjectCommandRepository(
+        context.db
+      );
+      const history = new ProjectHistoryRepository(context.db);
+      const command = createProjectSettingsUpdateProjectCommand({
+        singlePhaseVoltageV: 240,
+        threePhaseVoltageV: 415,
+      });
+      const forward = repository.executeUpdate({
+        projectId: "project-1",
+        expectedRevision: 0,
+        source: "user",
+        command,
+      });
+      assert.deepEqual(getSettings(context), {
+        singlePhaseVoltageV: 240,
+        threePhaseVoltageV: 415,
+        currentRevision: 1,
+      });
+      assert.deepEqual(forward.inverse.payload, {
+        singlePhaseVoltageV: 230,
+        threePhaseVoltageV: 400,
+      });
+
+      const undoStep = history.getNextCommand("project-1", "undo");
+      assert.ok(undoStep);
+      repository.executeUpdate({
+        projectId: "project-1",
+        expectedRevision: 1,
+        source: "undo",
+        historyTargetChangeSetId: undoStep.changeSetId,
+        command: forward.inverse,
+      });
+      assert.deepEqual(getSettings(context), {
+        singlePhaseVoltageV: 230,
+        threePhaseVoltageV: 400,
+        currentRevision: 2,
+      });
+
+      const redoStep = history.getNextCommand("project-1", "redo");
+      assert.ok(redoStep);
+      repository.executeUpdate({
+        projectId: "project-1",
+        expectedRevision: 2,
+        source: "redo",
+        historyTargetChangeSetId: redoStep.changeSetId,
+        command,
+      });
+      assert.deepEqual(getSettings(context), {
+        singlePhaseVoltageV: 240,
+        threePhaseVoltageV: 415,
+        currentRevision: 3,
+      });
+    } finally {
+      context.close();
+    }
+  });
+
+  it("rejects no-op, invalid project and stale revision without partial writes", () => {
+    const context = createTestDatabase();
+    try {
+      const repository = new ProjectSettingsProjectCommandRepository(
+        context.db
+      );
+      assert.throws(
+        () =>
+          repository.executeUpdate({
+            projectId: "project-1",
+            expectedRevision: 0,
+            source: "user",
+            command: createProjectSettingsUpdateProjectCommand({
+              singlePhaseVoltageV: 230,
+              threePhaseVoltageV: 400,
+            }),
+          }),
+        /did not change/
+      );
+      assert.throws(
+        () =>
+          repository.executeUpdate({
+            projectId: "missing",
+            expectedRevision: 0,
+            source: "user",
+            command: createProjectSettingsUpdateProjectCommand({
+              singlePhaseVoltageV: 240,
+              threePhaseVoltageV: 415,
+            }),
+          }),
+        /Project not found/
+      );
+      assert.throws(
+        () =>
+          repository.executeUpdate({
+            projectId: "project-1",
+            expectedRevision: 1,
+            source: "user",
+            command: createProjectSettingsUpdateProjectCommand({
+              singlePhaseVoltageV: 240,
+              threePhaseVoltageV: 415,
+            }),
+          }),
+        ProjectRevisionConflictError
+      );
+      assert.deepEqual(getSettings(context), {
+        singlePhaseVoltageV: 230,
+        threePhaseVoltageV: 400,
+        currentRevision: 0,
+      });
+      assert.equal(
+        context.db.select().from(projectRevisions).all().length,
+        0
+      );
+    } finally {
+      context.close();
+    }
+  });
+
+  it("rolls back both values and revision after a late history failure", () => {
+    const context = createTestDatabase();
+    try {
+      context.sqlite.exec(`
+        CREATE TRIGGER fail_project_settings_history
+        BEFORE INSERT ON project_history_stack_entries
+        BEGIN
+          SELECT RAISE(ABORT, 'forced project settings history failure');
+        END;
+      `);
+      const repository = new ProjectSettingsProjectCommandRepository(
+        context.db
+      );
+      assert.throws(
+        () =>
+          repository.executeUpdate({
+            projectId: "project-1",
+            expectedRevision: 0,
+            source: "user",
+            command: createProjectSettingsUpdateProjectCommand({
+              singlePhaseVoltageV: 240,
+              threePhaseVoltageV: 415,
+            }),
+          }),
+        /forced project settings history failure/
+      );
+      assert.deepEqual(getSettings(context), {
+        singlePhaseVoltageV: 230,
+        threePhaseVoltageV: 400,
+        currentRevision: 0,
+      });
+      assert.equal(
+        context.db.select().from(projectRevisions).all().length,
+        0
+      );
+    } finally {
+      context.close();
+    }
+  });
+});

tests/project-state-restore-command.repository.test.ts

@@ -21,6 +21,7 @@ import { ProjectDeviceStructureProjectCommandRepository } from "../src/db/reposi
 import { ProjectHistoryRepository } from "../src/db/repositories/project-history.repository.js";
 import { ProjectSnapshotRepository } from "../src/db/repositories/project-snapshot.repository.js";
 import { ProjectStateRestoreCommandRepository } from "../src/db/repositories/project-state-restore-command.repository.js";
+import { ProjectSettingsProjectCommandRepository } from "../src/db/repositories/project-settings-project-command.repository.js";
 import { readProjectStateSnapshot } from "../src/db/repositories/project-state-snapshot.persistence.js";
 import { circuitDeviceRows } from "../src/db/schema/circuit-device-rows.js";
 import { circuitLists } from "../src/db/schema/circuit-lists.js";
@@ -136,6 +137,7 @@ function createService(context: DatabaseContext) {
     new ProjectDeviceStructureProjectCommandRepository(context.db),
     new ProjectDeviceProjectCommandRepository(context.db),
     new ProjectDeviceRowSyncProjectCommandRepository(context.db),
+    new ProjectSettingsProjectCommandRepository(context.db),
     new ProjectStateRestoreCommandRepository(context.db),
     new ProjectHistoryRepository(context.db)
   );