fix(review-suite): mark example verification commands as placeholders; pin variable description and prompt note

Adversary re-review follow-ups to 665fee9/402d25a:

- architect/sisyphus spawn templates: the pinned cargo commands are only an
  EXAMPLE in a language-agnostic orchestrator — a literal follower in a
  non-Rust repo would record 'cargo: command not found' and yield a false
  DIVERGES. Each --variables line now carries a substitution cue (pinned).
- run_checks.py: a non-list prior pipeline_faults value is no longer iterated
  character by character (test case added).
- Pins: both graphs' verification_commands description wording; the
  run_adversary prompt states where the commands come from; the replacement
  sentence sits on one physical line.

assets/agents/review-gauntlet/graph.yaml

@@ -333,8 +333,7 @@ nodes:
       The spec / plan / acceptance criteria it must satisfy:
       {{plan_context}}
 
-      Verification commands arrive as a structured input (the
-      verification_commands variable), not in this prompt.
+      Verification commands arrive as a structured input (the verification_commands variable), not in this prompt.
 
       {{extra_context}}