fix(#829): harden runtime launch guard against marker evasions

docs/architecture/mutator-class-gate.md

@@ -37,9 +37,11 @@ The executable submits the runtime's actual tool name to `authorize_tool`. Missi
 
 ## Runtime-launch choke-point and permanent guard
 
-Every repository-owned Claude/Pi launch entry converges on `launch-runtime.py`, either directly or through `mosaic` → `execLeaseGatedRuntime`. PRDY init/update and QA remediation invoke the wrapper directly so their existing prompts, dangerous-permission flags, working directory, and environment survive without skipping broker registration. `@mosaicstack/coord` rewrites direct Claude commands to `mosaic claude` and rejects unknown custom Claude launchers.
+Every repository-owned Claude/Pi launch entry converges on `launch-runtime.py`, either directly or through `mosaic` → `execLeaseGatedRuntime`. PRDY init/update and QA remediation invoke the wrapper directly so their existing prompts, dangerous-permission behavior, working directory, and environment survive without skipping broker registration. The raw Claude `--dangerously-skip-permissions` primitive is owned only by `launch-runtime.py`; callers request semantic `--dangerous` mode, and the wrapper validates Claude before injecting the primitive. `@mosaicstack/coord` rewrites direct Claude commands to `mosaic claude` and rejects unknown custom Claude launchers.
 
-`check-runtime-launches.py` is the permanent completeness guard. It scans production shell, TypeScript/JavaScript, Python, and data launch definitions under `packages/`, `apps/`, `plugins/`, and `tools/`; direct literal, absolute-path, process-API, and dynamic runtime launches fail. It is mandatory in `@mosaicstack/mosaic`'s test script, so root CI fails when a future entry does not name the wrapper, `execLeaseGatedRuntime`, or a gated `mosaic` launch. Synthetic scanner tests prove representative bypass forms are rejected, while real-socket tests prove PRDY init/update and QA receive broker sessions and deny an unverified mutator.
+`check-runtime-launches.py` is the permanent completeness guard. It scans production shell, TypeScript/JavaScript, Python, and data launch definitions under `packages/`, `apps/`, `plugins/`, and `tools/`; direct literal, absolute-path, process-API, dynamic, command-substitution, `eval`, and variable-execution runtime launches fail. Shell comments are stripped with quote awareness, wrapper prefixes are tokenized with `shlex`, and only an invocation in command position with `--runtime` before the command separator is gated. A direct command always wins over an inert marker on the same line. Independently, the raw dangerous primitive anywhere outside the choke-point is RED.
+
+Both checks are load-bearing: command-position analysis covers consequential launches that do not use dangerous mode, while primitive ownership cannot be fooled by a comment or marker string for dangerous mode. The guard is mandatory in `@mosaicstack/mosaic`'s test script, so root CI fails on a future bypass. Permanent regressions cover the original add-ungated effectiveness probe, comments, strings, assignments, heredocs, continuations, command chains, command substitution, `eval`, and variable execution; real-socket tests prove PRDY init/update and QA receive broker sessions and deny an unverified mutator.
 
 The live inventory is emitted by:
 

docs/scratchpads/829-mutator-gate.md

@@ -110,3 +110,8 @@ Carried authority chain also verified/read for the locked T-B gate contract: SPE
 - 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.
+- Round-4 GREEN uses both defenses. Quote-aware comment stripping removes shell/Python `#` and JS/TS line/block comments; shell command prefixes are segmented with `shlex`; validated wrappers require `launch-runtime.py` in command position, `--runtime`, and the `--` command separator; multiline TypeScript wrapper calls are validated as complete invocations. Direct command syntax wins over markers, while tracked runtime assignments plus `eval`/variable execution, command substitution, chained commands, heredocs, continuations, and `env`/`command`/`nohup` prefixes are rejected.
+- Primitive ownership is independently load-bearing: `launch-runtime.py` is the sole production owner of the raw Claude dangerous flag. Mosaic, Claudex, and PRDY request semantic `--dangerous`; the wrapper validates Claude and injects the primitive immediately before register/exec. This preserves actual YOLO argv behavior while making any raw primitive elsewhere fail without relying on wrapper-name recognition.
+- 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.