test(spec): keep the blank-string row name short enough to print whole

vitest prints a table row's `$name` truncated past about forty characters, so
the rewritten row now states its decision in a name that prints whole.

Claude-Session: https://claude.ai/code/session_01T9u38rswFp5Rw8DswRUReJ
Co-authored-by: Claude <noreply@anthropic.com>

Author: claude

packages/spec/src/automation/flow-decision-branch-expression-absent.test.ts

@@ -63,7 +63,7 @@ const TABLE: Array<{ name: string; branch: Node; refused: boolean; refusedWith?:
   { name: 'no `expression` key', branch: { label: 'y' }, refused: true, refusedWith: undefined },
   { name: '`expression: null`', branch: { label: 'y', expression: null }, refused: true, refusedWith: null },
   { name: 'the predicate under the edge\'s spelling `condition`', branch: { label: 'y', condition: 'true' }, refused: true, refusedWith: undefined },
-  { name: 'a blank string — the control: a blank predicate is already refused', branch: { label: 'y', expression: '   ' }, refused: true, refusedWith: '   ' },
+  { name: 'a blank string — blanks are refused', branch: { label: 'y', expression: '   ' }, refused: true, refusedWith: '   ' },
   { name: 'a real predicate — the accept control', branch: { label: 'y', expression: 'true' }, refused: false },
 ];