003 mismatch must error

// TEST: Auto-proc synthesis must fail when shapes don't match
//
// MUST_FAIL: Missing proc
//
// When input/output don't match, the compiler cannot synthesize a proc.
// This event has different field names - no auto-synthesis possible.

~import "$std/io"

// Input has 'input_val', output has 'output_val' - MISMATCH
~pub event mismatched { input_val: i32 }
| done { output_val: i32 }

// This should fail - no proc and can't synthesize
~mismatched(input_val: 42)
| done d |> std.io:print.ln("should not reach here")