Enhance dashboard guild access with owner bypass functionality

- Introduced `resolveDashboardGuild` to handle guild resolution for both managed and owner-panel bypass scenarios.
- Updated `GuildLayout` and `WelcomePage` components to utilize the new guild resolution logic, improving access handling.
- Enhanced `DashboardShell` to display an informational banner for users accessing guilds via the owner-panel bypass.
- Added localization support for owner bypass messages in English and German.
- Updated authentication logic to allow owner-panel users to access guilds without Discord Manage Guild permission.

apps/webui/src/lib/auth.ts

@@ -3,6 +3,7 @@ import { NextResponse } from 'next/server';
 import { ZodError } from 'zod';
 import { hasManageGuildPermission } from '@nexumi/shared';
 import { fetchDiscordUserGuildsCached } from './discord-oauth';
+import { hasOwnerGuildBypass } from './owner-auth';
 import { prisma } from './prisma';
 import { getSession, type SessionPayload } from './session';
 
@@ -46,19 +47,25 @@ export async function requireAuthOrRedirect(): Promise<SessionPayload> {
 /**
  * Ensures the current session user has Manage Guild permission on the given
  * guild (via Discord OAuth guild list) and that the bot is actually installed
- * there (tracked via the `Guild` table). Use in API routes.
+ * there (tracked via the `Guild` table). Owner-panel users bypass Discord
+ * membership checks. Use in API routes.
  */
 export async function requireGuildAccess(guildId: string): Promise<SessionPayload> {
   const session = await requireAuth();
+  const dbGuild = await prisma.guild.findUnique({ where: { id: guildId } });
+  if (!dbGuild) {
+    throw new ForbiddenError('Nexumi is not installed on this server');
+  }
+
+  if (await hasOwnerGuildBypass(session.user.id)) {
+    return session;
+  }
+
   const guilds = await fetchDiscordUserGuildsCached(session.accessToken);
   const guild = guilds.find((entry) => entry.id === guildId);
   if (!guild || !hasManageGuildPermission(guild.permissions)) {
     throw new ForbiddenError('Missing Manage Guild permission for this server');
   }
-  const dbGuild = await prisma.guild.findUnique({ where: { id: guildId } });
-  if (!dbGuild) {
-    throw new ForbiddenError('Nexumi is not installed on this server');
-  }
   return session;
 }
 
@@ -68,15 +75,20 @@ export async function requireGuildAccess(guildId: string): Promise<SessionPayloa
  */
 export async function requireGuildAccessOrRedirect(guildId: string): Promise<SessionPayload> {
   const session = await requireAuthOrRedirect();
+  const dbGuild = await prisma.guild.findUnique({ where: { id: guildId } });
+  if (!dbGuild) {
+    redirect('/dashboard');
+  }
+
+  if (await hasOwnerGuildBypass(session.user.id)) {
+    return session;
+  }
+
   const guilds = await fetchDiscordUserGuildsCached(session.accessToken);
   const guild = guilds.find((entry) => entry.id === guildId);
   if (!guild || !hasManageGuildPermission(guild.permissions)) {
     redirect('/dashboard');
   }
-  const dbGuild = await prisma.guild.findUnique({ where: { id: guildId } });
-  if (!dbGuild) {
-    redirect('/dashboard');
-  }
   return session;
 }