Add print cover fields and office profile

- Project settings gain siteAddress, workStage, projectLead and
  projectEditor (project.update-settings schema version 3, migration 0009);
  versions 2 and 1 stay executable and keep the current cover values.
  Snapshot schema 6 carries the fields; older versions upgrade with null.
- Global office profile (office name/address) next to the document logo:
  table document_branding_settings, PUT /api/document-branding/office,
  editable from the print view toolbar.
- Cover page reads all fields; empty values show the "[ergänzen]" marker.
  The Planstände editor column shows the project editor.
- Shared logo constants moved to a dependency-free module so the Next.js
  bundler can import them.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/db/repositories/project-state-snapshot.persistence.ts

@@ -46,6 +46,10 @@ export function readProjectStateSnapshot(
       threePhaseVoltageV: projects.threePhaseVoltageV,
       enabledDistributionBoardSupplyTypes:
         projects.enabledDistributionBoardSupplyTypes,
+      siteAddress: projects.siteAddress,
+      workStage: projects.workStage,
+      projectLead: projects.projectLead,
+      projectEditor: projects.projectEditor,
       currentRevision: projects.currentRevision,
     })
     .from(projects)
@@ -249,6 +253,10 @@ export function readProjectStateSnapshot(
       threePhaseVoltageV: project.threePhaseVoltageV,
       enabledDistributionBoardSupplyTypes:
         project.enabledDistributionBoardSupplyTypes,
+      siteAddress: project.siteAddress,
+      workStage: project.workStage,
+      projectLead: project.projectLead,
+      projectEditor: project.projectEditor,
     },
     distributionBoards: boardRows,
     externalCsvConfiguration,