paper(§5): add roofline, capacity planning, parallelism selection subsections

Three new subsections at the top of §5, motivated by the deployment-sizing
questions the analytical visualization tool exposes:

- 5.1 Roofline Analysis — B*, L*, short vs long context batch effect
  (measured: 19× per-token cost reduction at short context, 28% at long)
- 5.2 Capacity Planning — 3-axis sizing (weights / KV / SLO), SLO targets,
  regime rules, deployment templates, per-axis playbook
- 5.3 Parallelism Selection — TP × CP × PP × DP × EP comparison,
  symptom-driven axis selection, add/stop criteria, misconceptions

Restructure:
- 05-gqa.tex trimmed to section header + intro
- Existing 5.4-5.7 content (placement, short/long ctx, composite) moved
  to 05x-fused-kernel.tex
- Summary extracted to 05z-summary.tex, cross-refs updated
- main.tex \input order sets the requested subsection sequence
- lmodern loaded to satisfy microtype font-expansion

Two new figures generated from tests/analytical_visualization/chip_roofline:
- roofline_short_context.png (S_kv=8K, batch wins)
- roofline_long_context.png (S_kv=1M, batch stalls at KV floor)
- Generator: tests/analytical_visualization/_gen_roofline_paper_figs.py

4 tables (regime rules, deployment templates, playbook, parallelism
criteria) use table* so they span both columns without overflow.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/report/1H-codesign-paper/sections/05z-summary.tex

@@ -0,0 +1,22 @@
+\subsection{Summary}
+\label{sec:gqa-analysis}
+
+The section's results line up into one picture of the fused kernel.
+Placement is decided by memory first and communication second: only the
+64-way splits fit production context, and among them the both-axes
+sequence shard (Case~6) minimizes the per-token collective by merging
+softmax state rather than partial scores. Command form is decided by
+roofline position: the composite command removes the per-tile issue work
+in both regimes, but converts to wall-clock only in compute-bound prefill,
+while memory-bound decode stays bound by KV streaming regardless of command
+form. The thread connecting the two is that, once composite issue makes
+GEMM cheap and leaves the MAC array idle, the fused kernel's latency is set
+almost entirely by data movement---streaming the KV cache and reducing
+partials across PEs---which is exactly the cost the communication-side
+work (on-device reduction, lazy load/compute overlap, fast TCM staging and
+torus links) is built to attack. Roofline framing
+(\S\ref{sec:roofline}) turns this observation into a sizing and sharding
+programme in the next two subsections: capacity planning
+(\S\ref{sec:capacity-planning}) and parallelism selection
+(\S\ref{sec:parallelism-selection}). What this implies for hardware
+investment across the report as a whole is taken up in the discussion.