[Fix] (DirectVulkan, ShaderTranspiler, MG_IntegrationTest, SelfTest, TraceReplay): use native subgroups and patch iterationRP's under-declared scratch

iterationRP's Program 203 declares shared vec2 prefixSumCache[32] for a
512-invocation workgroup indexed by gl_SubgroupID; any device narrower
than 16 lanes partitions into more than 32 subgroups and the pack writes
shared memory out of bounds (heap corruption on lavapipe's CPU
rasterizer, ssim 0.028 on the CI retrace). Fix it where the fault lies -
in the fixture - and keep the GL contract sound everywhere else:

- FixIterationRPSubgroupScratchPass: fingerprint-gated SPIR-V pass that
  grows exactly that array to ceil(invocations/width) entries on sub-16-lane devices; every other module passes through byte-identical.
- DeriveNumSubgroupsPass stays default-on for the Adreno topology bug
  and is made spec-sound: pipelines request REQUIRE_FULL_SUBGROUPS
  whenever the workgroup shape makes the flag legal (computeFullSubgroups
  enabled, local_size_x a multiple of the native width, subgroup count
  within maxComputeWorkgroupSubgroups).
- EmulateSubgroupsPass: 32-lane virtual-subgroup lowering kept in-tree
  as a last resort, enabled only by MOBILEGL_MAGMA_EMULATE_SUBGROUP=1 on
  devices with no native subgroup support; fails closed on extended
  subgroup instructions and on modules whose added scratch would exceed
  maxComputeSharedMemorySize.
- IterationRPFirstReductionScenario skips gracefully outside the pack's
  16..256-lane source domain; the new IterationRPScratchFixScenario runs
  the fixture-shaped reduction on any width and asserts the exact
  width-independent total. DriverPost keeps reporting FAIL on
  out-of-domain devices.
- Program203 -> IterationRP rename throughout; the per-trace
  num_subgroups_quirk plumbing is removed from the trace replayer, JNI
  chain, and CI workflows.

.github/workflows/apk.yml

@@ -435,9 +435,6 @@ jobs:
           if [ "${{ matrix.case.coherent_as_flush || false }}" = "true" ]; then
             extra_retrace_args+=(--coherent-as-flush)
           fi
-          if [ "${{ matrix.case.num_subgroups_quirk || false }}" = "true" ]; then
-            extra_retrace_args+=(--num-subgroups-quirk)
-          fi
 
           run_retrace() {
             timeout "$(( ${{ matrix.case.timeout_seconds }} + 300 ))" sh android-plugin/trace-replay-ci.sh \