Add print view, board info card and document logo upload

- Seitenansicht (/projects/:projectId/print): tabular cover page, board
  overview with supply structure and power sums, one plan per board with a
  repeating title block; PDF via the browser print dialog with named @page
  rules (A4 portrait cover, A4/A3 landscape plans, page x of y).
- Distribution-board info card (board number, location, fed-from, remark)
  in the board edit dialog, persisted through the additively extended
  distribution-board.update command (migration 0008, snapshot schema 6,
  legacy subtree commands normalized).
- Global document logo upload (PNG/JPEG/SVG, max 2 MB) outside project
  revisions and snapshots.
- fed-from stays free text; the overview hierarchy and cumulated sums are
  preliminary until the feed link is modeled.

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

src/shared/validation/document-branding.schemas.ts

@@ -0,0 +1,25 @@
+import { z } from "zod";
+
+export const documentLogoMimeTypes = [
+  "image/png",
+  "image/jpeg",
+  "image/svg+xml",
+] as const;
+
+export type DocumentLogoMimeType = (typeof documentLogoMimeTypes)[number];
+
+export const maxDocumentLogoBytes = 2 * 1024 * 1024;
+
+export const uploadDocumentLogoSchema = z
+  .object({
+    fileName: z.string().trim().min(1).max(200),
+    mimeType: z.enum(documentLogoMimeTypes),
+    contentBase64: z
+      .string()
+      .min(1)
+      // Base64 expands by 4/3; the decoded size is checked again server-side.
+      .max(Math.ceil((maxDocumentLogoBytes * 4) / 3) + 4),
+  })
+  .strict();
+
+export type UploadDocumentLogoInput = z.infer<typeof uploadDocumentLogoSchema>;