fix(#829): enforce repository-wide runtime launch choke point

docs/scratchpads/829-mutator-gate.md

@@ -89,3 +89,15 @@ Carried authority chain also verified/read for the locked T-B gate contract: SPE
 - Mechanical repository sweep found direct executing Claude entries in PRDY init, PRDY update, QA remediation, and `@mosaicstack/coord` task launch. It also found a direct Claude command rendered into the QA report template and documentation examples. Existing Mosaic CLI Claude/Pi/Claudex, orchestrator session-run, and fleet starts already reach the gated boundary.
 - Elevated hard requirements: ship a permanent suite/CI guard that scans production source and fails on any direct Claude/Pi launch; route every executing entry through one common gated wrapper; add real-broker RED/GREEN tests for PRDY init/update and QA; preserve each environment and denial behavior; independently measure all new executable coverage at ≥85%.
 - Round-3 plan: first commit RED behavioral and scanner-contract tests; then add one framework `launch-runtime.sh` choke-point over `launch-runtime.py`, make Mosaic CLI and shell launchers use it, make coord route through `mosaic`, and wire the permanent guard into package tests. Update all discovered operator-facing direct-launch examples so the scanner inventory remains complete.
+
+### Round-3 outcome
+
+- RED commit `7f3418fa`: PRDY init, PRDY update, and QA remediation all reached the fake Claude binary without a broker session even when the configured socket did not exist; the permanent-guard contract initially failed because its executable was absent, then failed against the five discovered direct entries (four executing plus the QA command template).
+- Choke-point decision: a new shell layer was unnecessary. Every executing repository entry now converges directly or through `mosaic`/`execLeaseGatedRuntime` on the existing single `launch-runtime.py` register-then-exec wrapper. PRDY and QA preserve their working directories, prompts, flags, logging pipe, and environment. Coord rewrites direct Claude commands to `mosaic claude` and rejects unknown custom Claude launchers fail-closed.
+- Permanent guard: `packages/mosaic/framework/tools/lease-broker/check-runtime-launches.py`, invoked by `packages/mosaic/package.json` `test:framework-shell` and therefore root `pnpm test`/CI. It scans production code under `packages/`, `apps/`, `plugins/`, and `tools/` and rejects literal, absolute-path, process-API, command-array, and dynamic Claude/Pi launch forms. Synthetic bypass tests are permanent at `runtime_launch_guard_unittest.py`.
+- Mechanical inventory: **14 gated / 14 total** — coord 2, fleet 1, QA 2, orchestrator 3, PRDY 2, Mosaic Claude/Pi/Claudex adapter/boundary 4. No verification-layer fallback or follow-up issue is needed because the single code-level wrapper was achieved.
+- Real-socket behavioral evidence: PRDY init, PRDY update, and QA remediation each fail before runtime execution when the broker is absent; with the broker present they receive a broker-minted 64-hex session and the unverified `Bash` authorization exits 2. Claudex normal/YOLO and the broker state machine remain GREEN.
+- Fresh branch coverage: `launch-runtime.py` **18/18 = 100%**; `mutator-gate.py` **22/22 = 100%**; permanent guard **36/38 = 95%**; `daemon.py` WI-2 delta **35/40 = 87.5%**. All attributable executable statement coverage is at least 98%.
+- Fresh focused suites: broker + mutator real-socket acceptance `49/49`; persistence `10/10`; launcher/gate branch suite `13/13`; permanent guard suite `7/7`; coord `19/19`.
+- Fresh full repository suite: `43/43` Turbo tasks; `@mosaicstack/mosaic` `72/72` files and `1,384/1,384` tests. Root typecheck `42/42`, lint `23/23`, format, and diff checks GREEN.
+- PR #837 remains open and unmerged. Terra CODE and Opus SECREV must both rerun from zero on the exact round-3 head before coordinator-owned merge authorization.