Use session role for invite page, handle stale user sessions gracefully

Switch invite page from DB query (user.me) to JWT session for role checks,
avoiding failures when user ID is stale. Return friendly error from user.me
instead of throwing on missing user.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/routers/user.ts

@@ -19,7 +19,7 @@ export const userRouter = router({
    * Get current user profile
    */
   me: protectedProcedure.query(async ({ ctx }) => {
-    return ctx.prisma.user.findUniqueOrThrow({
+    const user = await ctx.prisma.user.findUnique({
       where: { id: ctx.user.id },
       select: {
         id: true,
@@ -41,6 +41,15 @@ export const userRouter = router({
         lastLoginAt: true,
       },
     })
+
+    if (!user) {
+      throw new TRPCError({
+        code: 'UNAUTHORIZED',
+        message: 'User session is stale. Please log out and log back in.',
+      })
+    }
+
+    return user
   }),
 
   /**