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>

docs/circuit-list-editor-api.md

@@ -230,9 +230,13 @@ returns HTTP `409` with `PROJECT_HISTORY_OPERATION_UNAVAILABLE`.
   - stale revisions return `409 PROJECT_REVISION_CONFLICT`
 - `PUT /projects/:projectId/distribution-boards/:distributionBoardId`
   - body:
-    `{ "floorId": null, "supplyType": "AV", "expectedRevision": 13 }`
-  - executes `distribution-board.update`; floor and supply type are restored
-    together by persistent Undo/Redo
+    `{ "floorId": null, "supplyType": "AV", "simultaneityFactor": 1, "expectedRevision": 13 }`
+  - optional info-card fields: `boardNumber` (max. 50), `location`,
+    `fedFrom` (max. 200 each) and `remark` (max. 2000); strings are trimmed
+    and an empty string is stored as `null`
+  - executes `distribution-board.update`; all submitted values, including the
+    submitted info fields, are restored together by persistent Undo/Redo
+  - `fedFrom` is free text until the logical feed link is modeled
 - `POST /projects/:projectId/distribution-boards/:distributionBoardId/copy`
   - body: `{ "name": "UV-02 Kopie", "expectedRevision": 14 }`
   - duplicates the complete distribution-board subtree with new owning UUIDs
@@ -425,3 +429,23 @@ project device never triggers synchronization implicitly.
 Parser errors expose stable codes such as `header-not-found`,
 `ambiguous-header`, `invalid-ifc-guid` and `duplicate-ifc-guid`. The confirmed
 import uploads and parses the file again and verifies its hash.
+
+## Document Branding (print view)
+
+Office-wide branding for the print view. These endpoints are mounted at
+`/api/document-branding`, outside `/api/projects`, because the data is global
+and intentionally not part of project revisions, snapshots or transfer.
+
+- `GET /document-branding`
+  - returns `{ "logo": { "mimeType", "fileName", "sizeBytes", "updatedAtIso" } | null }`
+- `GET /document-branding/logo`
+  - returns the stored image bytes with its media type, or `404` without logo
+  - responses carry `X-Content-Type-Options: nosniff` and a restrictive
+    Content-Security-Policy so an SVG logo cannot execute scripts
+- `PUT /document-branding/logo`
+  - request: `{ "fileName": "logo.png", "mimeType": "image/png", "contentBase64": "..." }`
+  - accepted types: `image/png`, `image/jpeg`, `image/svg+xml`; at most 2 MB
+    after decoding; the content signature must match the declared type
+  - replaces an existing logo; returns the logo metadata
+- `DELETE /document-branding/logo`
+  - removes the logo; returns `204`