test(#829): extend guard evasion matrix and primitive invariant

docs/scratchpads/829-mutator-gate.md

@@ -108,3 +108,5 @@ Carried authority chain also verified/read for the locked T-B gate contract: SPE
 - Reproduced RIDER E exactly at head `1792b7934dda7eff64a207b8b0edb9c460d4164b`: a temporary production file containing `exec claude --dangerously-skip-permissions "terra-r3" # launch-runtime.py` made the guard exit 0 and report `1 gated/1 total`.
 - Root cause: classification searched the unparsed physical line, and the broad gated regex treated any `launch-runtime.py` substring—including comments and inert arguments—as an invocation before the direct-launch finding was evaluated.
 - Round-4 plan: add permanent RED cases for the exact comment evasion plus string-argument, echo, and unrelated-variable marker evasions; tokenize/strip comments by launcher syntax; recognize only command-position wrapper invocations with `--runtime` and the gated command separator; retain 14/14 real inventory; rerun guard coverage and all gates fresh.
+- Mos Rider A/B decision: adopt **both** defenses. Command-position parsing remains necessary because a normal `claude -p` launch is consequential even without the dangerous flag. The primitive-location invariant is more mechanically robust for dangerous mode because it does not need to recognize a wrapper marker at all. Move the sole raw `--dangerously-skip-permissions` literal into `launch-runtime.py`; any occurrence in another production file is independently RED.
+- Rider-A RED matrix adds heredoc body, backslash continuation, non-first `;`/`&&`/pipe commands, command substitution, `eval`, and variable-execution indirection in addition to the six marker/comment evasions. Before the augmented implementation, primitive ownership, command substitution, `eval`, variable execution, and the preserved 14-site inventory all fail.