ekp/.phrase/phases/phase-kp-overhaul-20260726/change_configurable_break_policies_20260801.md

Change: Configurable Break Policies 2026-08-01

Superseded note: the historical hard-atom adjacency rule recorded below was removed by task036. Explicit atoms forbid only interior breaks; current final-pass reachability semantics are recorded in change_final_pass_emergency_stretch_20260802.md.

2026-08-01 — Plan task034 and record the red baseline

• Add task034 for configurable break policies and the remaining orphan-glyph quality failure in the 280px showcase paragraph.
• Modify the text-property layout spec to make inline code wrapping, token policies, kinsoku profiles, overlong-token behavior, buffer measure, and region break-policy precedence explicit.
• Modify the text-property layout plan with M13, preserving the approved architecture: resolve policy intervals before tokenization, compile to the existing hyphen/break vectors before DP, and keep the C boundary at 15 arguments and 15 batch fields.
• Red baseline: the latest screenshot shows the previous atom cascade is gone, but the crafted inline-code paragraph still permits pathological single-CJK source lines around the atom, including 行, 内, and 永. The implementation oracle must reject any such single-CJK source line when a legal non-emergency alternative exists.
• Verification contract: focused RED/GREEN ERT for core, buffer, command, cache, and diagnostics; C/Elisp parity; 300-case property fuzz; warning-as-error Elisp compilation; C builds/tests; checkdoc/package/static release gates; and reviewed fullscreen GUI evidence for inline wrapping, no orphan glyph, explicit no-break, block verbatim, measure modes, and overlong-token modes.
• Behavior/Risk: Planning records only. Runtime behavior is unchanged. This entry opened task034; later entries record its implementation and closure.

2026-08-01 — Record task034 implementation and G004 GUI evidence

• Modify task034, M13, and the text-property layout spec with verified implementation facts from G002/G003/G004. At this point task034 was still open pending later gates; G006 closure is recorded below.
• Implementation evidence recorded: core policy compilation preserves the existing C boundary; buffer policy ownership separates block skip faces from inline faces; public local/profile/region controls and diagnostics exist; showcase verification distinguishes automatic inline code from explicit ekp-no-break and verbatim block code.
• GUI evidence recorded: G004 passed GUI verifier ERT 7/7 and the clean single-window evidence run at /tmp/ekp-g004-evidence.Tp77dW reports 12/12 checkpoints with no failed assertions, 25.75s/206-frame recording, no black segments, automatic inline wrapping 3→2→3 lines across 280→340→280, every internal inline split as source whitespace, exact source, zero overlays, C active, and a settled no-hyphen→normal policy transition with stale nil-plan spans at zero.
• Verification status: G005 repository-wide gates and G006 cleanup are recorded below.
• Behavior/Risk: Documentation synchronization only in this entry. Do not close task034 or any user-confirmation issue from this G004-only evidence at this point in the sequence.

2026-08-01 — Record G005 final performance and repository gate evidence

• Modify task034 and the policy-boundary postmortem with the confirmed G005 root causes and final gate evidence. At this point task034 was still open pending G006 cleanup; G006 closure is recorded below.
• Root causes recorded: paragraph identity included unconditional policy measure, causing paragraph rebuilds; volatile property clearing fragmented equal property runs; policy analysis ran before paragraph-cache hits; and repeated same-paragraph/same-width requests duplicated semantic plan assembly.
• Fix evidence recorded: policy measure was removed from the semantic signature; adjacent equal filtered intervals are canonicalized; policy full analysis now uses a bounded two-tier cache keyed by clean source, canonical layout and raw face policy intervals, policy signature, and width context, with a measure tier only for actual width-sensitive no-break/overflow candidates; and semantic plans use a bounded per-paragraph plan cache. G007 later strengthened the consumer boundary from shallow copies to consumer-owned copies of plan-owned mutable payloads; see the G008 entry below.
• Performance evidence recorded: formal four-interleaved evaluator reports layout parity true. Core baseline p50/p95 was 38.6679/51.6782ms and candidate p50/p95 was 21.7102/33.0040ms, for 43.8549%/36.1354% gains. Resize baseline p50/p95 was 43.3831/55.6250ms and candidate p50/p95 was 22.0919/32.8202ms, for 49.0773%/40.9973% gains. Both candidate p95 values are under 50ms and both gain sets exceed 20%.
• Live evaluator recorded: the source-instrumented locked goal remains the known validation_failed debt; parity, zero-work, GC, conflict, and all-width-nonregression checks are true. Current C p95/p99 is 26.449/26.740ms, a 76.65%/77.23% improvement. Current Elisp p95/p99 is 49.940/52.017ms, a 91.64%/91.35% improvement. This is consistent with historical open issue018 and is not a regression.
• Production public-path evidence recorded: three byte-compiled runs passed with zero GC. C append p99 was 1.361-1.368ms and hard p99 was 1.876-1.891ms. Elisp append p99 was 1.692-1.775ms and hard p99 was 2.100-2.230ms.
• Verification recorded: default ERT passed 262/262; seeded permuted ERT seed 20260728 passed 255/255; isolated per-test process suite exited 0; the subsequently added alias guard passed targeted verification; property fuzz passed 300/300; warning-as-error byte compilation passed; pinned package-lint at 35996f478d81e51dae4fa30d051f741895d07399 exited 0 with only an external obsolete warning from the local names dependency; checkdoc was empty; release, 49-entry dictionary manifest, pinned dictionary update, shell syntax, CI YAML, and diff-check passed; portable, native, debug, and sanitize C builds were warning-clean; module 1.6/4-thread smoke passed; and focused C verification passed 19/19 including the 15-argument/15-field boundary.
• Verification status: G005 gates are complete. G006 cleanup is recorded below.

2026-08-01 — Close task034 with G006 cleanup evidence

• Modify task034, M13, the global change index, and the policy-boundary postmortem with G006 cleanup evidence.
• Cleanup evidence recorded: G006 edited only ekp.el and ekp-buffer.el, removing redundant policy/cache code without changing the locked behavior.
• Verification recorded: targeted cleanup suites passed 6/6 and 3/3; full core ERT passed 125/125; full buffer ERT passed 120/120; warning-as-error byte compilation passed; diff-check passed; and the C build gate passed.
• Behavior/Risk: task034 is closed for developer implementation, repository gates, performance gates, and cleanup gates. issue021 remains open pending user visual confirmation. Independent final code/architecture review has not yet been claimed.

2026-08-01 — Resolve G006/G007 review blockers with G008 ownership fixes

• Modify task034, M13, developer documentation, changelog, and postmortems with the G007/G008 ownership and backend-contract corrections.
• Review blockers resolved: G006 cleanup's independent review found that shallow semantic-plan copies left nested line/gap/glue payloads mutable through cache hits, and that malformed non-nil C results could still be treated too softly. G007 changed the semantic-plan cache boundary to return consumer-owned copies of every plan-owned mutable payload: source string, context, boxes, offsets, lines, glues, gaps, and signatures. para remains intentionally shared because paragraph-cache ownership and append identity rely on that object. G007 final review then found one remaining alias: copy-tree did not copy strings inside the returned context, so mutating a dynamic policy suffix from the returned plan could poison the cached context. G008 resolves that final blocker by using the recursive context copier for cons/vector/string payloads both when the context snapshot/cache key is created and when a plan is returned.
• Backend contract recorded: only a nil whole C result or nil per-item breaks may fall back to Elisp. Any malformed non-nil single or batch output signals ekp-backend-contract-error. The C entry remains 15 arguments and the batch payload remains 15 fields.
• Hard-atom boundary recorded: the ordinary boundary immediately before a following explicit ekp-no-break atom is forbidden before DP. This direct pre-DP adjacency rule is separate from the final-pass emergency-stretch model and is locked by a focused regression.
• Verification recorded: formal resize parity is true; core baseline p50/p95 is 36.595/48.357ms and candidate p50/p95 is 23.266/36.363ms, for 36.42%/24.80% gains. Resize baseline p50/p95 is 41.443/53.541ms and candidate p50/p95 is 23.761/36.889ms, for 42.67%/31.10% gains. ERT passes 268/268; property fuzz passes 300/300; release gates pass; byte-compiled current public path records zero GC with C append/hard p99 1.440-1.464/2.022-2.050ms and Elisp append/hard p99 1.648-1.687/2.136-2.335ms, all below 16ms.
• Behavior/Risk: G007 resolved the first recorded G006 review blockers, and G008 resolves the final string-leaf context blocker, but this change record does not claim final independent APPROVE/CLEAR. issue021 remains open pending user visual confirmation, and historical issue018 remains open.

2026-08-02 — Record final independent review clearance

• Review remediation: the first final code-review pass found warning-only defects in changed test fixtures and a stale C README setter example. The fixtures now byte-compile with warnings as errors, and the README documents the optional eighth EMERGENCY-STRETCH argument.
• Verification: the remediation-focused ERT passes 5/5, full ERT passes 288/288, every changed test file compiles warning-clean, and diff-check passes.
• Independent verdicts: the code-reviewer re-review returns APPROVE with zero findings; the subsequent architect review returns CLEAR and confirms core K-P ownership, content-independent final-pass reachability, Elisp/C parity, stable ABI, cache ownership, and complete nonempty GUI oracles.
• Behavior/Risk: task034 and its independent developer gate are complete. issue021 closed after the user's 2026-08-02 visual confirmation, and historical issue018 remains open.