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/schema/projects.ts

@@ -21,5 +21,9 @@ export const projects = sqliteTable("projects", {
     .$type<DistributionBoardSupplyType[]>()
     .notNull()
     .default(sql`'["AV","SV","EV","USV","MSR","SiBe"]'`),
+  siteAddress: text("site_address"),
+  workStage: text("work_stage"),
+  projectLead: text("project_lead"),
+  projectEditor: text("project_editor"),
   currentRevision: integer("current_revision").notNull().default(0),
 });