009 no handler silent

// Test 918i: Optional Branches - No |? and No Handler
//
// Verifies:
// 1. Handler has NO |? catch-all
// 2. Optional branch fires at runtime with no handler
// 3. Expected: silently ignored (optional = truly optional)

~import "$std/io"

// Event with required + optional branches
~event process { value: u32 }
| success { result: u32 }        // REQUIRED
| ?warning { msg: []const u8 }   // OPTIONAL

~proc process {
    if (value > 100) {
        return .{ .warning = .{ .msg = "Value too large" } };
    }
    return .{ .success = .{ .result = value * 2 } };
}

// value=10 → success → handled normally
~process(value: 10)
| success _ |> std.io:print.ln("SUCCESS")
// No |? — that's OK

// value=150 → warning → no handler, no |? → silently ignored
~process(value: 150)
| success _ |> std.io:print.ln("SUCCESS")
// No warning handler, no |? — optional branch fires into the void