ADR: add 0038-0042 (pcie_ep, pe_mmu, pe_tcm, sram, tiling)

Fill component-model coverage gaps surfaced by /report's G4 analysis.
Each ADR documents the component's First action, latency model, and
honest notes on dormant code or implementation asymmetries discovered
during re-evaluation against current code.

- 0038 pcie_ep: thin protocol-overhead model; ComponentBase forwarding
  worker as-is; named-node contract for router helpers
- 0039 pe_mmu: component + utility dual role; sub-page region stopgap;
  D2.1 flags pipeline path missing mmu.overhead_ns timeout (asymmetric
  with non-pipeline; not visible at default tlb_overhead_ns=0)
- 0040 pe_tcm: dual-channel BW serialization (read/write Resource cap=1);
  TcmRequest schema owned by TCM; timing-only (no data store)
- 0041 sram: terminal scratchpad model + ResponseMsg on reverse path;
  D1.1 flags _worker override as currently dormant (no Transaction
  actually targets the SRAM node today)
- 0042 tiling: pure plan-generator module, not a component; corrects
  the G4 misclassification; pins GEMM/Math stage sequences and
  epilogue scope contract

Also: /report skill G3 refinement — only flag older->newer asymmetric
cross-references; newer->older (e.g., 0034-0037 citing infrastructure
ADRs) are expected one-way and no longer reported.

Bilingual pair verifier (tools/verify_adr_lang_pairs.py) passes.

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

.claude/commands/report.md

@@ -62,6 +62,10 @@ After writing the document, report to the user in the chat response:
 - **G2 gaps** — ADRs missing **Context** or **Decision**. Alternatives
   and Consequences are optional; their absence is NOT a gap.
 - **G3 gaps** — ADR cross-references without a back-reference.
+  Only flag when the referencer's ADR number is **less than** the
+  referenced ADR's number (older → newer). Newer ADRs citing older
+  infrastructure ADRs (higher number → lower number) are expected to
+  be one-way and are NOT flagged.
 - **G4 suggestions** — areas where an ADR seems missing based on the
   ADR corpus + SPEC reading. Phrase as suggestions, not findings. Each
   G4 item must say *why* it's suggested and remain falsifiable.
@@ -99,7 +103,10 @@ For each `docs/adr/ADR-NNNN-*.md`:
 - Record presence/absence of **Context** and **Decision** for G2.
   Alternatives and Consequences presence is recorded for use during
   authoring, but their absence is not a gap.
-- Record ADR-NNNN cross-references for G3.
+- Record ADR-NNNN cross-references for G3, preserving the direction
+  (referencer → referenced). G3 evaluation uses ADR numbers to
+  distinguish older→newer (flagged when missing back-link) from
+  newer→older (not flagged; see *Output Contract* G3).
 - Record Status (e.g., Accepted, Superseded, Draft) and any "supersedes
   ADR-NNNN" text in the body for G5a.
 
@@ -263,9 +270,11 @@ In **dry-run mode**, replace the `Wrote:` line with:
 - ADR-NNNN: missing <Context|Decision>
 - (or "none")
 
-**G3 — Broken cross-references**
-- ADR-NNNN cites ADR-MMMM; ADR-MMMM does not back-reference
+**G3 — Broken cross-references** (older → newer only)
+- ADR-NNNN cites ADR-MMMM (NNNN < MMMM); ADR-MMMM does not back-reference
 - (or "none")
+- Note: newer ADRs citing older infrastructure ADRs (NNNN > MMMM) are
+  not flagged here — one-way references are the expected pattern.
 
 **G4 — Suggested topics that may warrant a new ADR (verify before acting)**
 - <topic>: <why agent thinks it may be missing — must be falsifiable>