test(#829): regress prefixed runtime variable launches

docs/scratchpads/829-mutator-gate.md

@@ -115,3 +115,9 @@ Carried authority chain also verified/read for the locked T-B gate contract: SPE
 - Permanent guard suite now has 10 tests and 31 direct-launch forms, including 18 new round-4 marker/comment/indirection/prefix evasions plus harmless-marker and multiline-wrapper controls. Terra's exact add-ungated source is exercised through the CLI effectiveness test. Repository inventory remains exactly **14 gated / 14 total**.
 - Fresh round-4 coverage: guard **97%** branch-aware aggregate (241 statements, 110 branches); `launch-runtime.py` **100%**; `mutator-gate.py` **100%**. The daemon is byte-unchanged from the round-3 head whose WI-2 delta is **87.5%**.
 - Fresh round-4 gates: real-socket acceptance **49/49**; persistence **10/10**; launcher/gate **14/14**; guard **10/10**; coord **19/19**; Mosaic **1384/1384**; root **43/43**; typecheck **42/42**; lint **23/23**; format and diff checks green.
+
+## Remediation round 5 — terra 18116 + Opus 18114
+
+- Both independent gates converged on one guard-only completeness gap at round-4 head `1eb77c17f3147d4fa9944f77f1826243135b9cc0`; all round-4 primitive anchoring, command-position parsing, 14/14 inventory, broker ordering, and coverage remain locked-good.
+- Reproduced exactly: a temporary production source containing `launcher=claude` followed by `exec "$launcher" -p x` exits 0 with `0 gated / 0 total`. The literal command resolver skips prefixes but cannot resolve a tracked variable; the variable resolver handles only bare/eval references and cannot skip prefixes.
+- Round-5 plan: add 10 permanent RED forms (quoted/unquoted `exec`, `command`, `nohup`, and `env` with assignment, each multiline and same-line), then unify shell command-position resolution so literal and tracked-variable terminal tokens traverse the same prefix parser. Retain an independent variable-reference backstop, the 14/14 inventory, and every round-4 regression.