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.ShaderCompiler/Gen5ShaderIr.cs

@@ -312,7 +312,8 @@ public sealed record Gen5VertexInputBinding(
     uint OffsetBytes,
     byte[] Data,
     int DataLength,
-    bool DataPooled);
+    bool DataPooled,
+    bool PerInstance = false);
 
 public sealed record Gen5ShaderEvaluation(
     IReadOnlyList<uint> InitialScalarRegisters,

src/SharpEmu.ShaderCompiler/Gen5ShaderScalarEvaluator.cs

@@ -883,8 +883,11 @@ public static class Gen5ShaderScalarEvaluator
         Gen5ShaderInstruction instruction,
         Gen5BufferMemoryControl control,
         BufferDescriptor descriptor) =>
+        // AGC embedded fetch is BufferLoadFormat/TBufferLoadFormat with idxen.
+        // offen is allowed: the constant/scalar offset folds into OffsetBytes
+        // (UI glyph shaders use this shape). Rejecting offen left those loads
+        // as live SSBOs and dropped vertex attributes.
         control.IndexEnabled &&
-        !control.OffsetEnabled &&
         control.DwordCount is >= 1 and <= 4 &&
         descriptor.BaseAddress != 0 &&
         descriptor.Stride != 0 &&