Fundament: Audit mit IP/User-Agent, Mail-Absender je Mandant

- Migration audit_request_context: ip_address, user_agent an audit_logs (Spec §26)
- writeAuditLog/writePlatformAudit erfassen IP (X-Forwarded-For) und User-Agent
  aus dem Request; außerhalb eines Requests (Worker/Skripte) null
- Audit-Viewer liest die neuen Spalten statt Heuristik aus before/after
- deliverMail nutzt Anzeigename und Reply-To aus TenantSettings (Spec §33.2);
  Absenderadresse bleibt Plattform-Domain (SPF/DKIM), Header-Injection bereinigt

Gate: tsc, lint, build, 24/24 Tests grün.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

prisma/migrations/20260914150000_audit_request_context/migration.sql

@@ -0,0 +1,3 @@
+-- Spec §26: audit entries carry IP address, user agent and outcome.
+ALTER TABLE "audit_logs" ADD COLUMN "ip_address" TEXT;
+ALTER TABLE "audit_logs" ADD COLUMN "user_agent" TEXT;

prisma/schema.prisma

@@ -284,6 +284,8 @@ model AuditLog {
   entityId  String?  @map("entity_id")
   before    Json?
   after     Json?
+  ipAddress String?  @map("ip_address")
+  userAgent String?  @map("user_agent")
   createdAt DateTime @default(now()) @map("created_at")
 
   tenant Tenant? @relation(fields: [tenantId], references: [id])

src/server/audit.ts

@@ -1,20 +1,42 @@
 import { prisma } from "./db";
 
 /**
- * Audit trail (SPEC §5 AuditLog, §10): every writing action creates an entry.
+ * Audit trail (spec §26): every writing action creates an entry.
  * Uses the raw client on purpose — audit writes must never be silently
  * filtered, and tenantId is passed explicitly by the caller.
  */
+
+type AuditAction = "create" | "update" | "delete" | "login" | "logout" | "export" | "import" | "denied";
+
+/**
+ * IP address and user agent of the current request, if there is one.
+ * Outside a request scope (workers, scripts, tests) `headers()` throws → both null.
+ * Behind the Coolify/Traefik proxy the client IP is the first X-Forwarded-For hop.
+ */
+async function requestContext(): Promise<{ ipAddress: string | null; userAgent: string | null }> {
+  try {
+    const { headers } = await import("next/headers");
+    const h = await headers();
+    const forwarded = h.get("x-forwarded-for")?.split(",")[0]?.trim();
+    const ip = forwarded || h.get("x-real-ip")?.trim() || null;
+    const ua = h.get("user-agent");
+    return { ipAddress: ip ? ip.slice(0, 64) : null, userAgent: ua ? ua.slice(0, 512) : null };
+  } catch {
+    return { ipAddress: null, userAgent: null };
+  }
+}
+
 export async function writeAuditLog(entry: {
   tenantId: string;
   actorId?: string;
-  action: "create" | "update" | "delete" | "login" | "logout" | "export" | "import" | "denied";
+  action: AuditAction;
   scope?: "tenant" | "platform";
   entity: string;
   entityId?: string;
   before?: unknown;
   after?: unknown;
 }) {
+  const ctx = await requestContext();
   await prisma.auditLog.create({
     data: {
       tenantId: entry.tenantId,
@@ -25,6 +47,8 @@ export async function writeAuditLog(entry: {
       entityId: entry.entityId,
       before: entry.before as object | undefined,
       after: entry.after as object | undefined,
+      ipAddress: ctx.ipAddress,
+      userAgent: ctx.userAgent,
     },
   });
 }
@@ -35,12 +59,13 @@ export async function writeAuditLog(entry: {
  */
 export async function writePlatformAudit(entry: {
   actorId?: string;
-  action: "create" | "update" | "delete" | "login" | "logout" | "export" | "import" | "denied";
+  action: AuditAction;
   entity: string;
   entityId?: string;
   before?: unknown;
   after?: unknown;
 }) {
+  const ctx = await requestContext();
   await prisma.auditLog.create({
     data: {
       tenantId: null,
@@ -51,6 +76,8 @@ export async function writePlatformAudit(entry: {
       entityId: entry.entityId,
       before: entry.before as object | undefined,
       after: entry.after as object | undefined,
+      ipAddress: ctx.ipAddress,
+      userAgent: ctx.userAgent,
     },
   });
 }

src/server/mail/deliver.ts

@@ -1,5 +1,5 @@
 import { prisma } from "@/server/db";
-import { getMailConfig, mailFrom } from "./config";
+import { getMailConfig, mailFrom, type MailConfig } from "./config";
 import { getMailProvider } from "./provider-smtp";
 import { TransientMailError } from "./provider";
 import { renderTemplate } from "./templates";
@@ -42,12 +42,13 @@ export async function deliverMail(job: MailJob): Promise<{ messageId: string }>
   }
 
   const rendered = renderTemplate(job.template, job.locale, job.vars);
+  const sender = await tenantSender(job.mailLogId, config);
 
   try {
     const { messageId } = await provider.send({
-      from: mailFrom(config),
+      from: sender.from,
       to: job.to,
-      replyTo: config.replyTo,
+      replyTo: sender.replyTo,
       subject: rendered.subject,
       html: rendered.html,
       text: rendered.text,
@@ -89,3 +90,28 @@ export async function markMailFailed(mailLogId: string, error: string): Promise<
     data: { status: "failed", error: error.slice(0, 500) },
   });
 }
+
+/**
+ * Tenant-specific display name and reply-to (spec §33.2). The sender ADDRESS always stays
+ * the platform address (SPF/DKIM alignment); only the display name and Reply-To vary.
+ * Raw client on purpose: the worker has no tenant context; the MailLog row carries the tenant.
+ */
+async function tenantSender(mailLogId: string, config: MailConfig): Promise<{ from: string; replyTo?: string }> {
+  const log = await prisma.mailLog.findUnique({ where: { id: mailLogId }, select: { tenantId: true } });
+  if (!log?.tenantId) return { from: mailFrom(config), replyTo: config.replyTo };
+  const settings = await prisma.tenantSettings.findUnique({
+    where: { tenantId: log.tenantId },
+    select: { mailFromName: true, mailReplyTo: true },
+  });
+  const name = sanitizeDisplayName(settings?.mailFromName);
+  return {
+    from: name ? mailFrom({ ...config, fromName: name }) : mailFrom(config),
+    replyTo: settings?.mailReplyTo?.trim() || config.replyTo,
+  };
+}
+
+/** Strip characters that could break the From header (quotes, angle brackets, CR/LF). */
+function sanitizeDisplayName(v: string | null | undefined): string | null {
+  const cleaned = (v ?? "").replace(/[\r\n"<>]/g, "").trim().slice(0, 80);
+  return cleaned || null;
+}

src/server/services/audit/viewer.ts

@@ -100,19 +100,6 @@ export function diffAudit(before: unknown, after: unknown): DiffRow[] {
   });
 }
 
-/** Extract request metadata if a writer stored it (writeAuditLog does not capture it yet). */
-function requestMeta(...sources: unknown[]): { ip: string | null; userAgent: string | null } {
-  for (const s of sources) {
-    if (s && typeof s === "object") {
-      const o = s as Record<string, unknown>;
-      const ip = typeof o.ip === "string" ? o.ip : null;
-      const userAgent = typeof o.userAgent === "string" ? o.userAgent : null;
-      if (ip || userAgent) return { ip, userAgent };
-    }
-  }
-  return { ip: null, userAgent: null };
-}
-
 export async function getAuditEntry(ctx: ServiceCtx, id: unknown) {
   assertCan(ctx, "audit:read");
   const entryId = z.string().min(1).max(64).parse(id);
@@ -123,6 +110,8 @@ export async function getAuditEntry(ctx: ServiceCtx, id: unknown) {
     ...row,
     actorName: actor?.name ?? null,
     diff: diffAudit(row.before ?? undefined, row.after ?? undefined),
-    ...requestMeta(row.after, row.before),
+    // captured by writeAuditLog from the request (spec §26); null for worker/script writes
+    ip: row.ipAddress,
+    userAgent: row.userAgent,
   };
 }