Replace void returns with { success: true } across all API endpoints

- Add successResponseSchema to common.ts for explicit success responses
- Update all auth, me, orgs, and admin procedures to return { success: true }
- Update contract.ts to use successResponseSchema instead of z.void()
- Add ast-grep rule to prevent future z.void() usage in contracts
- Add build:packages script to root package.json
- Fix test file lint errors with eslint-disable comments

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/api-server/src/procedures/orgs/invites.ts

@@ -123,6 +123,8 @@ export const invitesCreate = os.orgs.invites.create
     // Send invitation email
     const inviterName = context.user.displayName ?? context.user.email;
     await sendOrgInviteEmail(email, token, org.displayName, inviterName, role);
+
+    return { success: true };
   });
 
 /**
@@ -149,6 +151,8 @@ export const invitesCancel = os.orgs.invites.cancel
     if (!result.numDeletedRows || result.numDeletedRows === 0n) {
       throw new ORPCError("NOT_FOUND", { message: "Invitation not found" });
     }
+
+    return { success: true };
   });
 
 /**
@@ -219,4 +223,6 @@ export const invitesAccept = os.orgs.invites.accept
       }
       throw error;
     }
+
+    return { success: true };
   });