gqa(adr): ADR-0064/0065 review fixes — composite size cap, type-aware logical_bytes, R recalibration

ADR-0064 Revision 2 review fixes:
- D7 NEW: composite size cap (MAX_COMPOSITE_LOGICAL_BYTES default 1024
  bytes). Oversized recipes deterministically segmented into N
  CompositeCmds; each segment incurs its own dispatch cost. Models real
  HW limits (descriptor queue entry, scheduler parser buffer, command
  SRAM) and prevents the model from rewarding pathologically-large
  fused composites.
- D2: type-aware extra-field byte counting (int/float=4, bool=1,
  tuple/list=1+4N, str=1) — replaces uniform 4 bytes per extra.
- D3: recalibrated defaults to FIXED=40 cycles, R=0.0625 cycles/byte
  (16 B/cycle — typical on-die descriptor queue width); anchor stays at
  ~43 ns for typical 1-OpSpec composite. Clarified anchor description:
  DMA stages do not appear in logical_bytes (auto-inserted by
  PE_SCHEDULER from operand.space per ADR-0065 D4).
- D4: removed clock_freq_ghz from pe_cost_model: override block;
  conversion uses the PE node's existing clock_freq_ghz attr. Added
  max_composite_logical_bytes knob.
- Context: emphasized command-count reduction (FIXED) as the primary
  signal; byte term as secondary refinement.
- Open review: added large-composite scheduler-cost stress test.
- Test req: added composite-size-cap (#8) and R-sensitivity sweep (#9).

ADR-0065 + DDD-0065 follow-on updates:
- opt2 vs opt3 dispatch ratio updated 2.4× → ≈4.0× under new defaults
  (FIXED-dominated, reflecting the corrected framing).
- Test req #9: decode opt2 composite fits within 1024-byte cap; no
  segmentation needed for the GQA workload.
- DDD §6: TLContext lowering checks logical_bytes against cap (step 8).
- DDD §11: performance model recomputed with new defaults + sensitivity
  table across R ∈ {0.25, 0.0625, 0.03125} confirming opt2 < opt3 holds.
- DDD §9 P6 gate: ratio band 2.4×±10% → 4.0×±15%; sensitivity sweep added.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/adr-proposed/ADR-0065-prog-flat-ops-composite-softmax-merge.md

@@ -338,9 +338,15 @@ input from #1's epilogue scratch — circular tile-loop dependency.
 6. **opt2 numeric parity with opt3.** In data mode, opt2's final
    `(m, l, O)` matches opt3's within fp tolerance.
 7. **opt2 dispatch ratio (after ADR-0064 Rev2).** opt3 vs opt2 per-tile
-   PE_CPU dispatch cycles ratio ≈ 2.4× at default calibration.
+   PE_CPU dispatch cycles ratio ≈ 4.0× at default calibration
+   (FIXED=40 cycles, R=0.0625 cycles/byte). Ratio is FIXED-dominated,
+   reflecting command-count reduction as the primary signal.
 8. **GEMM-count invariant.** A composite with two GEMM OpSpecs raises a
    validation error at TLContext emit.
+9. **Within composite size cap (ADR-0064 D7).** Decode opt2's `#2`
+   composite (10 ops, ~310 logical bytes) fits comfortably under the
+   default `MAX_COMPOSITE_LOGICAL_BYTES=1024` — no segmentation. The
+   recipe lowering test asserts `cmd.logical_bytes < 1024`.
 
 ## Dependencies