fix: address coderabbit review on #6214

- Remove invalid null return from session callback (must return session object)
- Prevent admin from disabling their own account (guard with isSelf check)
- Hide disable UI when viewing own profile
- Add user existence check to changeDisabled endpoint
- Add OpenAPI metadata to changeDisabled mutation

packages/api/src/router/user.ts

@@ -790,7 +790,29 @@ export const userRouter = createTRPCRouter({
       }),
     )
     .output(z.void())
+    .meta({
+      openapi: {
+        method: "PATCH",
+        path: "/api/users/disabled",
+        tags: ["users"],
+        protect: true,
+      },
+    })
     .mutation(async ({ input, ctx }) => {
+      const dbUser = await ctx.db.query.users.findFirst({
+        columns: {
+          id: true,
+        },
+        where: eq(users.id, input.userId),
+      });
+
+      if (!dbUser) {
+        throw new TRPCError({
+          code: "NOT_FOUND",
+          message: "User not found",
+        });
+      }
+
       await ctx.db
         .update(users)
         .set({