🎉 Mark D1.3 as SOLVED! SMEM-P rank mismatch fixed, enables hd>64 support

STAGE_D.md

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 # Stage D — Parameterized FMHA for DSV4
 
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+## 🎉 VICTORY: D1.3 SOLVED! (2026-05-23)
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+**After intensive debugging, SMEM-P rank mismatch issue resolved!**
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+**Problem:** SMEM-P copy failed with "Expected source and destination tensors to have the same rank, but got 5 and 3"
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+**Root Cause:**  tensor used TMEM layout () with extra singleton modes, while SMEM copy expected QK C-fragment layout.
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+**Solution:** Create  tensor viewing same data with QK C-fragment layout ():
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+**Impact:** Enables hd>64 support (128, 256, 512). Multi-PV-tile works for hd=512 (2 tiles of 256 each).
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+**Status:** Kernel compiles and runs for all head dimensions. SMEM-P path enabled for hd>64.
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 ## ⚠️ IKEA INSTRUCTIONS — READ EVERY TIME BEFORE CODING
 
 ### The Workflow (DO NOT SKIP STEPS)