Record manual acceptance and validate performance guards on current master

docs/performance/EXPERIMENTS.md

@@ -585,3 +585,46 @@ supports retaining the candidates in the isolated burndown branch for further
 qualification. Normal-speed audio/pacing, constrained-host comparisons,
 multi-title correctness and actual low-end hardware remain open. Do not ship
 the local uncap hook as a gameplay default.
+
+## MANUAL-INTEGRATION-004: user sign-off and master integration
+
+Date: 2026-09-05. The user reviewed the Tomba 2 and Mega Man X6 manual builds,
+reported that they "look good", and explicitly authorized committing and
+merging the work to main/master. This is user acceptance of the supplied test
+builds, not an instrumented audio comparison, full-title playthrough or a new
+performance measurement.
+
+Both manual builds used the combined guards from `04371d60`, normal pacing,
+OpenGL, recomp-ui, production debug-tools OFF, rewind ON, existing generated
+game/BIOS code and isolated copied memory cards. Recomp-ui displayed verified
+discs with BIOS paths supplied. Final executable SHA256 values:
+
+- Tomba 2: `6d978d8e2a736aa8b94cb076091117edbe76f6fa7c7f061df227233be8a648ad`.
+- Mega Man X6: `4c99e7a6092122b6675daf83f52eddb76a71b0b5290b474c7f4d494df84135b2`.
+
+The initial Tomba build disabled rewind to bypass a dependency lookup; review
+rejected that workaround and the final build restored rewind. Mega Man X6's
+older recomp-ui headers were incompatible with the runtime, so its manual
+build used the compatible Tomba 2 recomp-ui checkout. Neither original game
+installation was edited. Local build logs/settings/screenshots remain under
+the original burndown worktree's `.local/manual-validation` directory.
+
+Integration uses `origin/master` at `17f49ad3` as its base. Only the six campaign
+commits `6488414a`, `d38f97e1`, `8ec6498d`, `28e9c844`, `0cf93d57`, and
+`04371d60` were transplanted; the older review-branch ancestry was excluded.
+All six applied without conflicts. The runtime delta remains only the three
+production diagnostic guards; benchmark uncapping and local game artifacts
+are not part of the merge.
+
+The first integration GPU test failed because its old polyline fixture supplied
+only one vertex before the terminator. Upstream now correctly requires two
+vertices. The fixture now supplies both; the upstream runtime fix is unchanged.
+On the integrated sources, all three actual-source guard regressions and the
+63 campaign/host/stall-report tests pass. The previously tested game executables
+are not rebuilds of this newer upstream base; no such equivalence is claimed.
+The CMake registration guard also passes with 133 test files registered.
+
+Disposition: user-approved integration of the scoped optimizations, tests and
+measurement tools. The original WIP label records the historical state at
+implementation time. The broader burndown, general speedup qualification and
+actual low-end hardware coverage remain open after this merge.

docs/performance/RUNTIME_AUDIT.md

@@ -16,6 +16,10 @@ threading or Vulkan behavior has changed.
 [PACER-COST-001](EXPERIMENTS.md#pacer-cost-001-attribute-idle-pacing-cpu-cost)
 provides idle-pacer CPU attribution, not a speedup claim.
 
+[MANUAL-INTEGRATION-004](EXPERIMENTS.md#manual-integration-004-user-sign-off-and-master-integration)
+records the user's Tomba 2/Mega Man X6 sign-off and approval to integrate the
+scoped guards. This does not close the wider performance/correctness campaign.
+
 ## Disposition Matrix
 
 | Area | Current disposition | Evidence | Candidate / next check | Correctness guardrails |

runtime/tests/test_gpu_gp0_history_guard.py

@@ -100,6 +100,8 @@ static void emit_copy(uint32_t src_xy, uint32_t dst_xy, uint32_t wh) {
 static void emit_polyline(void) {
     gpu_write_gp0(0x4800007Fu);
     gpu_write_gp0((20u << 16) | 10u);
+    /* The first two vertices are mandatory, before any terminator. */
+    gpu_write_gp0((25u << 16) | 15u);
     gpu_write_gp0(0x55555555u);
     s_frame_count++;
     checkpoint();
@@ -466,7 +468,7 @@ def main() -> int:
     if prod_out["copydump"] != "0" or prod_out["polydump"] != "0":
         fail("production GP0 history frame dumps should be empty")
     if debug_out["total"] != "10" or int(debug_out["cap"]) == 0:
-        fail("debug GP0 history stopped recording")
+        fail(f"unexpected debug GP0 history: {debug_out}")
     if debug_out["src"] != "00123400" or debug_out["op"] != "e1":
         fail("debug GP0 history lost source/opcode tracking")
     if debug_out["cmd0"] != "e10003ff":