Record CP shared-KV C11-C14 closure evidence

C11-C14 are now tied to explicit remote verification instead of leaving the ledger at the intermediate failure state.  The mixed-version symbol issue is documented as a caller-sync problem, and the stale C14 expectations are recorded as intentional current contracts rather than open regressions.

Constraint: Local pytest in this workspace is blocked by missing optional runtime dependencies such as orjson, so remote g0034 container tests are the authoritative CPU/unit evidence for these files.

Rejected: Reintroduce cp_shared_kv_mla_prefetch_should_trace_tiny_extend | the current callers no longer import it, and adding a dead compatibility helper would hide sync mistakes.

Confidence: high

Scope-risk: narrow

Directive: Keep C13 validation focused on matching caller/runtime sync; do not resurrect stale helper APIs unless an active caller contract requires them.

Tested: Local py_compile for touched runtime/prefetch/caller/test files; remote caller import check printed CALLER_IMPORT_OK; remote exact C14 set passed 6 passed, 3 warnings; remote three-file suite passed 123 passed, 5 warnings.

Not-tested: CUDA/TAI ETE runtime logs were not rerun in this documentation-only commit.

Co-authored-by: OmX <omx@oh-my-codex.dev>

docs/advanced_features/nsa_prefill_cp_page_aligned_cache_contract.md

@@ -864,6 +864,24 @@ Tests:
 - Remote CUDA benchmark/runtime for the TAI materialize primitive and full ETE
   prefill run.
 
+Verified C12 CPU/unit slice:
+
+- Local syntax verification passed for the touched runtime/prefetch/caller/test
+  files with `python -m py_compile`.
+- Local targeted pytest remains blocked by the already-recorded local dependency
+  gap (`orjson` import via `sglang.srt.utils.common`), so this branch uses the
+  remote container as the authoritative unit-test environment for these files.
+- Remote container `g0034:/mnt/beegfs/cjy/sglang-dev` passed the three-file CPU
+  suite:
+
+  ```text
+  PYTHONPATH=python python -m pytest -q \
+    test/registered/unit/layers/test_nsa_cp_utils.py \
+    test/registered/unit/mem_cache/test_cp_shared_kv_layout.py \
+    test/registered/unit/mem_cache/test_cp_shared_kv_runtime.py
+  # 123 passed, 5 warnings
+  ```
+
 ### C13. Remote source sync can expose mixed-version symbols
 
 Current state:
@@ -898,10 +916,21 @@ Correction:
 
 Tests:
 
-- Import-level check:
-  `python - <<'PY' ... import cp_shared_kv_mla_prefetch_should_trace_tiny_extend`.
+- Import-level check for the matching caller set:
+  `import sglang.srt.layers.attention.nsa.nsa_indexer` and
+  `import sglang.srt.layers.attention.nsa_backend`.
 - Re-run the three-file remote pytest suite.
 
+Completed C13:
+
+- The stale helper
+  `cp_shared_kv_mla_prefetch_should_trace_tiny_extend` is intentionally not a
+  runtime API in the current code.  The fix was to sync matching caller files
+  (`nsa_indexer.py`, `nsa_backend.py`) with the current runtime instead of
+  reintroducing a dead compatibility helper.
+- Remote caller import check prints `CALLER_IMPORT_OK`.
+- The same remote three-file unit suite now passes (`123 passed, 5 warnings`).
+
 ### C14. Wider remote unit suite still exposes non-page-padding regressions
 
 Current state:
@@ -955,6 +984,36 @@ Tests:
 - Re-run the exact failed tests after each fix, then the three-file remote
   suite.
 
+Completed C14:
+
+- Updated the stale unit expectations to the intended contracts:
+  - direct-write fallback logs require
+    `[CP_SHARED_KV_FALLBACK][direct_write]`;
+  - MLA/index prefix materialize is recorded on the current stream while async
+    reduce is recorded on the prefetch stream;
+  - `wait_attention_window()` remains a deferred historical hook and does not
+    launch/wait pending reduce work;
+  - negative
+    `SGLANG_CP_SHARED_KV_MLA_PREFETCH_MIN_PREFIX_PAGES` values use the dynamic
+    default `max(cp_size, ceil(default_tokens / page_size))`, so
+    `cp_size=4,page_size=64` returns `8` with the current 512-token default.
+- Remote exact C14 regression set passed:
+
+  ```text
+  test_local_out_cache_loc_logs_every_fallback_event
+  test_mla_prefetch_materializes_on_current_stream_and_reduces_on_prefetch_stream
+  test_index_prefetch_materializes_on_current_stream_and_reduces_on_prefetch_stream
+  test_mla_prefetch_attention_window_does_not_launch_pending_reduce
+  test_index_prefetch_attention_window_defers_pending_event_wait
+  test_mla_prefetch_min_prefix_pages_uses_cached_token_default_and_can_override
+  # 6 passed, 3 warnings
+  ```
+- Remote three-file suite passed after sync:
+
+  ```text
+  123 passed, 5 warnings
+  ```
+
 ## Testing requirements
 
 Add targeted tests before implementation: