fix(agc): merge Prospero attrib-table formats onto IR vertex inputs (#556)

IR-discovered BufferLoadFormat often keeps a stale float sharp format;
patch DataFormat/offset from the AGC attrib table (semantic index),
allow offen fetches, and map quirks 113/121 through NarrowVk for host
vertex input.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/SharpEmu.Libs/Agc/AgcExports.cs

@@ -6488,6 +6488,32 @@ public static partial class AgcExports
             TraceAstroTitlePixelGlobalProbe(pixelEvaluation);
         }
 
+        // Patch BufferFormat from the attrib table onto the V# before host
+        // vertex input. IR discovery often keeps a stale float format from the
+        // unpatched sharp — that turns UI glyphs into gradient triangles.
+        // Match by stride+offset (not bare base address) so interleaved streams
+        // keep loading-video bindings intact.
+        if (exportEvaluation.VertexInputs is { Count: > 0 } discoveredInputs &&
+            AgcVertexMetadata.TryGetVertexTableRegisters(
+                ctx,
+                exportShaderAddress,
+                exportShaderHeader,
+                out var vertexTables))
+        {
+            var merged = AgcVertexMetadata.MergeVertexInputsFromMetadata(
+                ctx,
+                exportEvaluation.ScalarRegisters,
+                vertexTables,
+                discoveredInputs);
+            if (!ReferenceEquals(merged, discoveredInputs))
+            {
+                TraceAgcShader(
+                    $"agc.vertex_metadata_format es=0x{exportShaderAddress:X16} " +
+                    $"count={merged.Count}");
+                exportEvaluation = exportEvaluation with { VertexInputs = merged };
+            }
+        }
+
         // Every bound color target the shader exports to. Deferred renderers
         // draw a multi-render-target G-buffer (up to eight slots) in one pass.
         // Fall back to slot 0 if we cannot match any export to a bound target.
@@ -7269,6 +7295,7 @@ public static partial class AgcExports
                 Mix(input.NumberFormat);
                 Mix(input.Stride);
                 Mix(input.OffsetBytes);
+                Mix(input.PerInstance ? 1u : 0u);
             }
         }
 
@@ -8277,7 +8304,8 @@ public static partial class AgcExports
                 binding.OffsetBytes,
                 binding.Data,
                 binding.DataLength,
-                binding.DataPooled);
+                binding.DataPooled,
+                binding.PerInstance);
         }
 
         return buffers;