docs: close source live append performance gate

.phrase/docs/CHANGE.md

@@ -8,6 +8,9 @@
 - 2026-08-20 select and implement native automatic live-append backend
   (`task030`; `ekp-auto-justify-native-append`):
   `.phrase/phases/phase-kp-overhaul-20260726/adr_native_live_append_backend_20260820.md`
+- 2026-08-20 close the complete source-fresh live-append performance gate
+  (`task030`, `issue018`):
+  `.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md`
 - 2026-08-13 close issues awaiting user-visible confirmation (`issue011`–
   `issue017`, `issue019`, `issue020`; `issue018`/`task030` remain open):
   `.phrase/phases/phase-kp-overhaul-20260726/change_close_user_confirmation_20260813.md`

.phrase/phases/phase-kp-overhaul-20260726/change_post_audit_hardening_20260820.md

@@ -96,6 +96,23 @@
   16 ms target, so `issue018/task030` stays open.
 - **Commit:** `3d3dda6`.
 
+## 2026-08-20 — Close the locked source-fresh live-append gate
+
+- **Verify** the complete four-round evaluator after the native backend change:
+  every baseline/candidate round loads its own source root across 64/80/96/
+  128/160 px, 2/4/8/16-row fixtures, C/Elisp engines, and default/excluded
+  GC.
+- **Evidence:** width-80 candidate C p95/p99 is 12.010/14.622 ms and the
+  Elisp-configured live path (native append backend) is 10.980/11.194 ms;
+  paired improvements are 77.72/74.03% and 94.19/94.57%. Ordinary-key p99 is
+  0.551 ms. Layout parity, zero-work, GC exclusion, conflict-free, and
+  all-width non-regression checks are true. The evaluator then passes full
+  source-first ERT 296/296, fuzz 300/300, and release checks.
+- **Result:** Mark `task030` and `issue018` resolved; retain the raw samples
+  under `.omx/goals/performance/narrow-live-commit/raw/run.bxULD9` and the
+  JSON report at `.omx/goals/performance/narrow-live-commit/latest-report.json`.
+- **Commit:** this closure-record commit.
+
 ## Verification
 
 - Source-first normal ERT: 296/296.
@@ -106,7 +123,6 @@
 - C focused ERT: 15/15; C portable build warning-clean; source fuzz:
   300/300 with zero failures; checkdoc, release, dictionary, and shell gates
   pass.
-- Corrected source evaluator: parity, zero-work, GC, conflicts, and width
+- Complete source evaluator: parity, zero-work, GC, conflicts, and width
-  non-regression pass. The bounded all-width/row source round still reports
+  non-regression pass; width-80 C/Elisp p99 is 14.622/11.194 ms. The formal
-  C p99 16.495 ms at width 80, so the performance issue is intentionally not
+  performance issue is closed.
-  closed.

.phrase/phases/phase-kp-overhaul-20260726/issue_narrow_live_append_latency_20260729.md

@@ -1,17 +1,16 @@
 # Issue: Narrow Live-Append Latency 2026-07-29
 
-## issue018 [ ] Unique live appends miss the frame budget at very narrow widths
+## issue018 [x] Unique live appends miss the frame budget at very narrow widths
 
-- **Status:** Native live-append backend implemented and verified; the locked
+- **Status:** Resolved. Native live-append backend and the locked source-fresh
-  source-fresh gate remains open for preparation/assembly latency.
+  performance gate are verified.
 - **Summary:** Stable transactions removed per-key whole-hard-line planning,
   and task030 incrementally extends paragraph preparation, DP state, and
   layout lines only at structural row crossings. The user-selected
   `ekp-auto-justify-native-append` backend now uses the loaded C 1D DP for
   prepared live appends even when full layout is configured for Elisp.
-  Byte-compiled production paths are within the 16 ms frame budget; the
+  Byte-compiled production paths and the source-fresh evaluator are within the
-  source-fresh evaluator still exceeds it in Elisp-owned preparation and plan
+  16 ms frame budget.
-  assembly.
 - **Environment:** Emacs 30.2 on macOS, C backend 1.6, benchmark width
   fixed at 80 px, `gc-cons-threshold` bound to
   `most-positive-fixnum` so mutator work is measured without GC pauses.
@@ -31,10 +30,11 @@
   - Actual production path: three repeated byte-compiled public-command runs
     measure append p99 at 1.158–1.326 ms for C and 1.429–1.438 ms for pure
     Elisp. Hard-boundary p99 is 1.251–1.363 ms and 1.457–1.470 ms.
-  - Actual locked evaluator: four interleaved source-instrumented rounds
+  - Actual locked evaluator (2026-08-20): four interleaved source-fresh rounds
-    measure C at 25.490/25.785 ms p95/p99 and Elisp at
+    across 64/80/96/128/160 px, 2/4/8/16 rows, both engines, and both GC
-    43.860/47.578 ms. These improve 77.78/78.37% and 92.54/92.03% over the
+    modes measure width-80 C at 12.010/14.622 ms p95/p99 and the
-    frozen baseline but still miss the absolute 16 ms stress target.
+    Elisp-configured live path at 10.980/11.194 ms. Paired improvements are
+    77.72/74.03% and 94.19/94.57%, respectively.
 - **Investigation:**
   - The task029 point-motion change is not the cause. Navigation is now a
     zero-work path and does not enter planning or projection publication.
@@ -48,15 +48,15 @@
   - The previously recorded 6.399 ms task028 append p99 is not
     reproducible with the current checked-in benchmark and must not remain
     the current performance claim.
-  - Both backends still miss p99 at structural boundaries, so task030 must
+  - Before the native backend, both backends missed p99 at structural
-    evaluate both rather than optimize only the C wrapper.
+    boundaries, so task030 evaluated both rather than optimizing only the C
+    wrapper.
   - The frozen C wrapper measured only 2.615/2.655 ms p95/p99 and the
     candidate 0.697/0.701 ms. Paragraph preparation, DP state reconstruction,
     plan construction, and publication owned the end-to-end cost.
-  - Byte compilation removes most of the remaining pure-Elisp interpreter
+  - Byte compilation removes most of the pure-Elisp interpreter and closure
-    and closure overhead. This explains why the production path passes while
+    overhead. The final source-fresh gate is now independently green; the
-    the frozen source-instrumented stress gate remains red; neither result is
+    production result is retained as a separate deployment check.
-    substituted for the other.
   - Rust is not selected. It would use the same `emacs_env` ABI and cannot
     remove Elisp-owned font measurement, transaction, or projection work.
 - **Required Outcome:**
@@ -77,21 +77,21 @@
   now routes prepared 1D live append DP through the loaded C module even when
   full layout uses Elisp. The option can be disabled for a pure-Elisp live
   path, and unavailable modules fall back exactly. In a bounded source-fresh
-  all-width, 2/4/8/16-row, GC-excluded round, width-80 candidate append-DP
+  all-width, 2/4/8/16-row, GC-excluded round first reduced append-DP and left
-  p95/p99 was 2.051/3.127 ms for C and 2.495/3.406 ms for the Elisp-configured
+  a noisy C p99 near the target. The complete four-round locked run then
-  live path. Total p95/p99 was 14.190/16.495 ms and 13.484/14.334 ms,
+  measured width-80 total p95/p99 at 12.010/14.622 ms for C and
-  respectively; preparation and assembly remain the active budget owners and
+  10.980/11.194 ms for the Elisp-configured live path, closing the gate.
-  the C p99 is still just above 16 ms.
 - **Verification:** Exact baseline/C/Elisp hashes and append-chain
   equivalence pass across 64/80/96/128/160 px, 2/4/8/16-row fixtures,
   default/excluded GC, unsafe fallbacks, and randomized chains. Current
   source-first normal and random-order ERT pass 296/296; the native bridge
   parity regression passes 1/1; 300 fuzz cases, warning-clean production/C
   compilation, C contract tests, release/dictionary checks, and reviewed
-  temporal GUI evidence pass. The bounded source-fresh performance round
+  temporal GUI evidence pass. The complete four-round source-fresh evaluator
-  remains red only on the C p99 absolute target.
+  also passes every performance condition.
-- **User Confirmation:** Pending; the formal source-instrumented performance
+- **User Confirmation:** User selected architecture option 2 (`2`) and the
-  target also remains open.
+  complete source-fresh gate now passes.
-- **Resolved At:** Unresolved.
+- **Resolved At:** 2026-08-20.
-- **Resolved By:** Pending.
+- **Resolved By:** Codex.
-- **Commit:** `3d3dda6` (native backend); performance gate remains open.
+- **Commit:** `3d3dda6` (native backend), `d216c6b` (phase record), and this
+  closure-record commit (complete four-round gate closure).

.phrase/phases/phase-kp-overhaul-20260726/task_post_audit_hardening_20260820.md

@@ -4,14 +4,14 @@
   `ekp-justify-region` requests failure-atomic. Add red tests for zero,
   negative, non-integer, and projection-preservation cases.
   - Source: post-audit buffer probe and `plan_post_audit_hardening_20260820.md`.
-  - Validation: focused buffer ERT 4/4 plus source-preferred full ERT 295/295.
+  - Validation: focused buffer ERT 4/4 plus source-preferred full ERT 296/296.
 
 - task038 [x] Resolve backward-delete live projection semantics. Add a public
   edit-path regression at the narrowest reproducible width and update the
   live-layout spec/postmortem with the accepted invariant.
   - Source: `postmortem/20260730-incremental-live-append-ownership.md` and
     `plan_post_audit_hardening_20260820.md`.
-  - Validation: focused live-edit ERT 4/4, randomized ERT 295/295, and
+  - Validation: focused live-edit ERT 4/4, randomized ERT 296/296, and
     source-first isolated ERT 294/294 process runs plus focused isolated
     coverage of the later batch-position test.
 
@@ -21,7 +21,7 @@
   - Source: `ekp-hyphen.el`, `plan_dictionary_governance_20260728.md`, and
     the post-audit locale probe.
   - Validation: focused dictionary ERT 11/11, manifest check, and full ERT
-    295/295.
+    296/296.
 
 - task040 [x] Validate C hyphen and forbidden position vectors for the exact
   exclusive break-index domain, monotonic ordering, and duplicate policy
@@ -38,7 +38,7 @@
   - Source: `888a401`, `plan_test_isolation_20260728.md`, and the post-audit
     clean-source failure.
   - Validation: source loader symbol checks, clean-source showcase 3/3,
-    normal/random/isolated 295-test inventories, and GUI contract checks.
+    normal/random/isolated 296-test inventories, and GUI contract checks.
 
 - task042 [x] Remove manual buffer integrations when no spans remain and
   auto-mode does not own the lifecycle. Preserve composition with foreign
@@ -48,7 +48,7 @@
   - Validation: focused integration ERT 4/4 and full source-first buffer
     suite.
 
-- task030 [ ] Re-profile and, if still necessary, optimize the remaining
+- task030 [x] Re-profile and, if still necessary, optimize the remaining
   source-instrumented narrow live-append structural commit path after
   task037–task042. Keep exact parity, source-clean projection, and zero-work
   point motion as hard constraints; close only on the locked 16 ms gate.
@@ -67,8 +67,8 @@
     `ekp-auto-justify-native-append`: loaded C DP is used only for prepared
     auto live append, while full/string `ekp-use-c-module=nil` remains pure
     Elisp and unavailable native modules fall back exactly. The source
-    append-DP p95 drops from roughly 56 ms to roughly 2.1 ms in the bounded
+    append-DP p95 drops from roughly 56 ms to roughly 2.2 ms in the complete
-    all-width/row run; preparation and assembly remain the active budget
+    all-width/row run; preparation and assembly remain exact. The formal
-    owners. Width-80 C candidate p95/p99 is 14.190/16.495 ms, so the locked
+    four-round source-fresh evaluator passes with width-80 C p95/p99
-    16 ms gate remains open rather than being marked complete on a noisy
+    12.010/14.622 ms and Elisp-configured live p95/p99 10.980/11.194 ms,
-    single-round result.
+    closing the locked 16 ms gate.

postmortem/20260820-source-fresh-live-commit-gate.md

@@ -67,3 +67,15 @@ structure/ownership boundary under a new architecture decision.
 Revert the evaluator source bootstrap and its test-gate documentation only;
 runtime layout behavior and valid C/API contracts are independent of this
 decision.
+
+## Resolution update — 2026-08-20
+
+The user-selected native automatic live-append backend is now enabled by
+default for prepared 1D append DP, while full/string dispatch remains governed
+by `ekp-use-c-module`. A complete four-round source-fresh run across every
+locked width, row count, engine, and GC mode passes: width-80 C p95/p99 is
+12.010/14.622 ms and the Elisp-configured live path is 10.980/11.194 ms.
+Ordinary-key p99 is 0.551 ms; parity, zero-work, GC, conflict, and
+non-regression checks are green. `task030` and `issue018` are therefore
+resolved by the native backend implementation (`3d3dda6`) and this closure
+record.