[Perf] (MG_Backend): let DirectVulkan trust across frames what it proved once

The draw fast path still paid for its own proofs: the hottest single
load (20% of TrySetupDrawFastPath) was chasing the cold
VertexInputStateFactory heap entry just to answer "same vertex-input
layout?". That answer now comes from the frontend VAO's config-guarded
aux memo (layout hash + attribute masks), and a VAO-cycling stream with
a stable layout skips the pre-flight AND pipeline re-resolution
entirely. The VkProgramObject* is memoized on the snapshot behind a new
ProgramFactory cache-structure epoch (bumped on every insert/erase; use
is re-stamped so the idle sweep can never evict a live entry). A
render-state version move no longer forces the full path: the pipeline
value hash is refreshed in place and the 8-entry memo probed directly
(the GL_BLEND-toggle case).

The resolved-vertex-bindings memo now revalidates all-resident unmapped
entries ACROSS frames via per-binding slice epochs - minted from a
process-lifetime counter so a recycled address can never revalidate,
with every mutation path funnelled through BumpSliceEpoch - while
stamping each resource's GPU-use serial exactly as the skipped acquire
would, preserving the busy-tracking that glBufferSubData's
host-write-vs-staged-copy choice depends on. Resident index buffers get
the same treatment through an EBO slice memo.

The six-part dynamic-state tail (viewport/scissor/blend constants/depth
bias/line width/stencil) is gated behind one render-state-parameters
version + pass-geometry compare per command buffer. GetSlice is inlined;
SampledBindingsUnchanged walks only the program's declared bindings.

Quiet-box 6-round order-alternating A/B (on top of the frontend
VAO-bind commit): vanilla_draw -20.8% (790 -> 626 ns/op, 3.4x native to
2.5x), sampler_churn -28.2%, ubo_range -8.4%, state_toggle -3.8%;
tex_param's matrix flag (+10%) was adjudicated by an isolated
alternating re-run at +1.0% - position bias, not regression. Unit tests
421/421.

MobileGL/MG_Backend/DirectVulkan/Renderer/VertexInputStateFactory.cpp

@@ -71,6 +71,12 @@ namespace MobileGL::MG_Backend::DirectVulkan {
         }
         const BackendVertexInputState& entry = GetOrCreateVertexInputState(vao, GetOrComputeHash(vao));
         vao.SetBackendStateMemo(&entry, m_evictionEpoch);
+        // Also mirror the layout identity and the two per-draw masks into the VAO's aux
+        // memo (pure VALUES derived from the VAO configuration, so config-version
+        // guarding alone is sound). The draw fast path reads them from the VAO object it
+        // already touched instead of chasing into this entry - see PackVertexInputAuxMemo.
+        vao.SetBackendAuxMemo(entry.layoutHash,
+                              PackVertexInputAuxMasks(entry.unsupportedAttribMask, entry.attributeLocationMask));
         return entry;
     }