fix(logs): Crew-Unterschrift mit Benutzerzuordnung und Owner-Crew-Signatur

Klassische Crew-Signaturen speichern Unterzeichner und Datum; Export und UI zeigen die Zuordnung. Eigner ohne WRITE-Collaborators dürfen wieder als Crew per Passkey signieren.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/utils/signatures.ts

@@ -1,8 +1,13 @@
 import { hashEntryForSigning } from './entryCanonicalHash.js'
-import type { PasskeySignature, SignatureValue } from '../types/signatures.js'
+import type { ClassicSignature, PasskeySignature, SignatureValue } from '../types/signatures.js'
 
 export type SkipperSignStatus = 'none' | 'valid' | 'invalid'
 
+export interface SignatureAttribution {
+  username: string
+  signedAt: string
+}
+
 export function isSignatureImage(value: string | undefined | null): boolean {
   return typeof value === 'string' && value.startsWith('data:image/')
 }
@@ -16,9 +21,52 @@ export function isPasskeySignature(value: unknown): value is PasskeySignature {
   )
 }
 
+export function isClassicSignature(value: unknown): value is ClassicSignature {
+  return (
+    typeof value === 'object' &&
+    value !== null &&
+    (value as ClassicSignature).kind === 'classic' &&
+    (value as ClassicSignature).version === 1
+  )
+}
+
+export function getSignaturePayload(value: SignatureValue | '' | undefined | null): string {
+  if (!value) return ''
+  if (isClassicSignature(value)) return value.payload
+  if (isPasskeySignature(value)) return ''
+  return value
+}
+
+export function getSignatureAttribution(value: SignatureValue | '' | undefined | null): SignatureAttribution | null {
+  if (!value || typeof value === 'string') return null
+  if (isPasskeySignature(value) || isClassicSignature(value)) {
+    return { username: value.username, signedAt: value.signedAt }
+  }
+  return null
+}
+
+export function createClassicSignature(input: {
+  role: 'skipper' | 'crew'
+  userId: string
+  username: string
+  signedAt: string
+  payload: string
+}): ClassicSignature {
+  return {
+    kind: 'classic',
+    version: 1,
+    role: input.role,
+    userId: input.userId,
+    username: input.username,
+    signedAt: input.signedAt,
+    payload: input.payload
+  }
+}
+
 export function normalizeSignature(value: unknown): SignatureValue | undefined {
   if (value === null || value === undefined || value === '') return undefined
   if (isPasskeySignature(value)) return value
+  if (isClassicSignature(value)) return value
   if (typeof value === 'string') return value
   return undefined
 }
@@ -47,6 +95,7 @@ export async function getSkipperSignStatus(
 export interface SignatureExportLabels {
   imagePlaceholder: string
   passkeyLabel: (username: string, signedAt: string) => string
+  attributionLabel: (username: string, signedAt: string) => string
 }
 
 export function formatSignatureForExport(
@@ -57,15 +106,19 @@ export function formatSignatureForExport(
   if (isPasskeySignature(value)) {
     return labels.passkeyLabel(value.username, value.signedAt)
   }
+  if (isClassicSignature(value)) {
+    return labels.attributionLabel(value.username, value.signedAt)
+  }
   if (isSignatureImage(value)) return labels.imagePlaceholder
   return value
 }
 
 export function serializeSignature(value: SignatureValue | '' | undefined): SignatureValue | undefined {
   if (!value) return undefined
-  if (isPasskeySignature(value)) return value
-  if (isSignatureImage(value)) return value
-  const trimmed = value.trim()
+  if (isPasskeySignature(value) || isClassicSignature(value)) return value
+  const payload = typeof value === 'string' ? value : getSignaturePayload(value)
+  if (isSignatureImage(payload)) return payload
+  const trimmed = payload.trim()
   return trimmed || undefined
 }