---
title: v0.20.0 sub-item 1 bugfix — implementation plan
created: 2026-05-27
status: ACCEPT (round 2 closure — Phase B complete)
target_version: 0.20.0 (PR #189 force-update)
spec: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md
contract_sections: ["§9 (chunker_version cascade)"]
parent_plan: docs/superpowers/plans/2026-05-27-pdf-scanned-ocr-plan.md
review_history:
  - 2026-05-27 plan round 0 (opus, drafter) — 5 step group A-E, 18 sub-action
  - 2026-05-27 plan round 1 critic (opus, thorough) — NEEDS_DISCUSSION, HIGH 1 + MEDIUM 2 + LOW 3 + NIT 1 (7 finding)
  - 2026-05-27 plan round 1 verifier (opus, thorough) — NEEDS_DISCUSSION, HIGH 4 + MEDIUM 3 + LOW 4 + NIT 3 (14 finding)
  - 2026-05-27 plan round 1c rewrite (opus, drafter) — 21 finding 모두 적용 (critic 7 + verifier 14). detail = §8 round 1c rewrite changelog
  - 2026-05-27 plan round 2 closure critic (opus) — ACCEPT, 21/21 applied + 4 NIT cosmetic
---

# v0.20.0 sub-item 1 bugfix plan

> ACCEPT 된 spec (`docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md`, 965 lines, round 2 closure) 의 step decomposition. 3 bug (#2 walker code limit / #3 chunk_id collision Critical / #4 F4 fixture Pages tree) 의 force-update path (PR #189 base branch `feat/pdf-scanned-ocr` 위에 fix commits stack). **5 step (Group A-E), 18 sub-action, 4 commit + 1 verify-only step (= 5 step total, 4 commit boundary).** spec §6 의 16-row acceptance 가 본 plan 의 §4 verifier checklist 로 1:1 mapping.

## §0 Pre-flight + branch state

- **Branch**: `feat/pdf-scanned-ocr` (PR #189 base, HEAD = `b4d9e60` "chore(release): bump version 0.19.0 → 0.20.0"). 사용자 메모리 `feedback_pr_workflow` 따라 force-update path — 같은 branch 위에 fix commits 추가 + PR #189 force-push.
- **Working dir**: `/home/altair823/kebab`.
- **Env 강제** (`~/.claude/CLAUDE.md` "Disk Layout — 루트 디스크 보호가 최우선"):
  - `export CARGO_TARGET_DIR=/build/out/cargo-target/target` — XFS 4TB 전용 디스크 격리, repo root `target/` 생성 방지.
  - `export RELEASE_BIN="${CARGO_TARGET_DIR:-target}/release/kebab"` — release binary alias (Step 5 dogfood 의 모든 acceptance command 에서 사용).
  - `export TMPDIR=/build/cache/tmp` — 대용량 임시 파일 보호.
- **Cargo build 직렬화** (memory `feedback_serial_build_only`):
  - per-crate: `-j 4` default (예: `cargo test -p kebab-chunk -j 4`).
  - workspace: `-j 1` 강제 (`cargo test --workspace -j 1`, `cargo clippy --workspace -j 1` — 18 integration-test binary 동시 link 시 OOM).
- **`target/` clean policy** (memory `feedback_cargo_clean_policy`): `/build` XFS 4TB 분리라 routinely clean 금지. `df -h /build` 의 `Avail < 500G` OR `du -sh $CARGO_TARGET_DIR` > 200G 시에만 clean. Step 5 E1 의 first cargo invoke 직전 1 회 conditional check, 임계 미달 시 skip + commit body 안 "skipped cargo clean — /build avail X TB" 1줄 record.
- **dogfood KB layout 가정** (Step 5 E3 prerequisite, critic round 1 H-1 closure): canonical config path = `/build/cache/tmp/v0.20-dogfood/config.toml` (in-place, KB dir 안). 외부 backup file `/build/cache/tmp/v0.20-dogfood-config.toml` 은 **존재 안 함** — 본 plan 의 모든 acceptance command 는 in-place config 기준. Step 5 E3 의 KB clean 은 **destructive `rm -rf` 금지**, config 보존 selective clean 사용 (E3 detail 참조). dogfood config canonical path 는 본 §0 의 한 곳에서만 정의 — Step 5 E3 의 command 가 이 path 참조.
- **HOTFIXES.md / README / HANDOFF / ARCHITECTURE 영향**: Step 2 B4 가 HOTFIXES.md entry 추가 (Bug #3 second-iteration patch). 그 외 사용자 visible surface 변경 0 — README + HANDOFF + ARCHITECTURE 갱신 0 (CLI flag / wire schema / TUI key / config 추가 0; chunker_version bump 은 internal cascade 라 release notes 만).
- **wire schema 변경 0** — `ingest_progress.v1` + `ingest_report.v1` 추가 field 0. V00X migration 0. `chunks` table DDL unchanged.
- **frozen design contract 변경 0** — design §9 cascade rule 자체 변경 0 (rule 의 직접 적용으로 chunker_version 만 bump).
- **workspace version bump 0** — v0.20.0 이 이미 cut (commit `b4d9e60`). 본 plan 은 같은 v0.20.0 안의 cumulative bugfix (PR #189 force-update). Step 5 E5 의 PR force-push 만, release tag 재컷 0.

## §1 Plan overview + spec linkage

Spec §3 (Bug #2) + §4 (Bug #3) + §5 (Bug #4) 의 fix design 을 atomic step 으로 decompose. 핵심 sequencing:

1. **Bug #2 walker code limit fix** (Step 1) — `is_code_file` helper + walker conditional + unit test. spec §3.4 + §3.5 의 diff 그대로 적용. 1 commit.
2. **Bug #3 chunk_id fix + chunker_version bump** (Step 2) — `chunk_page` return tuple 4-tuple 확장 + caller `per_chunk_hash` suffix 를 `segment_start` 로 변경 + `VERSION_LABEL` `"pdf-page-v1"` → `"pdf-page-v1.1"` bump + module doc 갱신 + HOTFIXES.md entry + unit regression test. spec §4.4 + §4.4.1 + §4.5 의 diff 그대로 적용. 1 commit.
3. **Bug #3 integration test** (Step 3) — `crates/kebab-app/tests/` 안 multi-scanned PDF chunk_id collision-free integration test. spec §4.5.1 의 MockOcrEngine pre-condition 결정 (Option A share 또는 Option B inline) 이 executor 의 first sub-action. 1 commit.
4. **Bug #4 F4 fixture re-generation** (Step 4) — `tests/fixtures/_synth/mojibake.py` 의 pikepdf-based rewrite + F4 fixture binary regenerate + parse-pdf 의 3 신규 invariant test. spec §5.4 + §5.5 + §5.6 의 diff 그대로 적용. 1 commit.
5. **Workspace verify + commit + PR force-push** (Step 5) — cargo workspace test `-j 1` + clippy `-D warnings` + dogfood re-run (`/build/cache/tmp/v0.20-dogfood` isolated KB, qwen2.5vl:3b 의 Ollama endpoint `192.168.0.47:11434`) + PR #189 force-push. spec §6 16-row consolidated acceptance 가 본 step 의 verifier checklist.

ordering invariant:

- **Step 1 || Step 2 || Step 4 mutually independent**: 3 bug 의 fix 가 서로 다른 crate (`kebab-source-fs` / `kebab-chunk` / `tests/fixtures` + `kebab-parse-pdf`) 의 file path 에 한정 — 동시 진행 가능. 정합성 우선 → Step 1 → Step 2 → Step 4 sequential.
- **Step 2 < Step 3**: integration test 가 `kebab-chunk` 의 fix 된 chunk_id 계산 path 위에 의존. Step 2 의 GREEN 이 prerequisite.
- **Step 4 < Step 5 dogfood**: F4 fixture regeneration 의 결과 binary 가 dogfood 의 9 PDF 중 1 (mojibake) — Step 5 E3 dogfood 의 `block_count: 1` invariant 검증 prerequisite.
- **Step 1-4 all < Step 5 workspace test**: workspace 전체 test 가 production code + test 의 final state 위에서만 의미.

commit 단위는 logical group 1 commit (atomic) — §7 sequencing summary 의 5-commit table 따름. 사용자 memory `feedback_pr_workflow` (gitea-pr + 리뷰 루프) 따라 force-update 후 `gitea-pr-review` skill 의 review 루프 진입.

---

## §2 Step group structure (Group A-E)

| Step | Group | 분류 | sub-action |
|---:|---|---|---|
| 1 | A | Bug #2 walker code limit fix | A1 `is_code_file` helper + A2 walker conditional + A3 unit test |
| 2 | B | Bug #3 chunk_id collision fix + chunker_version bump | B1 `chunk_page` 4-tuple + B2 caller `per_chunk_hash` + B3 `VERSION_LABEL` bump + B4 module doc + HOTFIXES.md + B5 unit regression test |
| 3 | C | Bug #3 multi-scanned PDF integration test | C1 MockOcrEngine share decision + C2 integration test (conditional) |
| 4 | D | Bug #4 F4 fixture re-generation | D1 mojibake.py pikepdf rewrite + D2 fixture regenerate + commit + D3 parse-pdf 3 invariant test |
| 5 | E | Workspace verify + commit + PR force-push | E1 cargo workspace test -j 1 + E2 clippy -D warnings + E3 dogfood re-run + E4 commit + E5 PR #189 force-push |

---

## §3 Per-step detail

### Step 1 (Group A): Bug #2 walker code limit fix

spec §3 의 Option A (code path only) — `is_oversized` 호출을 `is_code_file(path)` conditional 로 gate. PDF/image/markdown 의 size 는 parser 단계 자체 검증 (lopdf load_mem 256 KB+ 정상, image OCR 의 max_pixels self-cap).

#### Sub-action A1 — `is_code_file` helper 추가

- **Files affected**: `crates/kebab-source-fs/src/code_meta.rs` (line 129 `is_oversized` 함수 직후, 또는 `code_lang_for_path` 정의 직후).
- **Action** (spec §3.4 diff 그대로):
  ```rust
  /// Returns true when `path`'s filename/extension is recognised as a code
  /// file (per `code_lang_for_path`). Used by the walker to apply
  /// `[ingest.code].max_file_bytes` / `max_file_lines` only to code files,
  /// not to PDF/image/markdown (which have their own size controls in
  /// their respective parsers).
  pub(crate) fn is_code_file(path: &Path) -> bool {
      code_lang_for_path(path).is_some()
  }
  ```
- **Acceptance**:
  - `grep -c "pub(crate) fn is_code_file" crates/kebab-source-fs/src/code_meta.rs` = **1**.
  - `cargo build -p kebab-source-fs -j 4` green.

#### Sub-action A2 — walker conditional size check

- **Files affected**: `crates/kebab-source-fs/src/connector.rs:168-190` (현재 verified line range).
- **Action** (spec §3.4 diff 그대로 — `is_oversized` 호출 앞에 `is_code_file` short-circuit):
  ```diff
  -            // Size-cap check (byte or line limit).
  -            if crate::code_meta::is_oversized(
  -                &abs_path,
  -                self.max_file_bytes,
  -                self.max_file_lines,
  -            )
  -            .unwrap_or(false)
  +            // v0.20.0 sub-item 1 bugfix (#2): size-cap applies ONLY to
  +            // code files. PDF/image/markdown bypass — their parsers
  +            // have their own size controls. spec §3.3.
  +            if crate::code_meta::is_code_file(&abs_path)
  +                && crate::code_meta::is_oversized(
  +                    &abs_path,
  +                    self.max_file_bytes,
  +                    self.max_file_lines,
  +                )
  +                .unwrap_or(false)
              {
                  fs_skips.skipped_size_exceeded =
                      fs_skips.skipped_size_exceeded.saturating_add(1);
                  ...
                  tracing::debug!(
                      path = %rel_path.display(),
                      max_bytes = self.max_file_bytes,
                      max_lines = self.max_file_lines,
  -                    "skip: file exceeds size cap"
  +                    "skip: code file exceeds size cap"
                  );
                  continue;
              }
  ```
- **Acceptance**:
  - `grep -nE "is_code_file\(&abs_path\)\s*$" crates/kebab-source-fs/src/connector.rs` ≥ **1**.
  - `grep -c "skip: code file exceeds size cap" crates/kebab-source-fs/src/connector.rs` ≥ **1**.
  - `cargo build -p kebab-source-fs -j 4` green.

#### Sub-action A3 — Bug #2 unit test 추가

- **Files affected**: `crates/kebab-source-fs/src/connector.rs` 의 기존 `#[cfg(test)] mod tests` (spec §3.5 "기존 test module 에 추가" 명시 — 새 file 아님).
- **Action** (spec §3.5 의 `size_cap_skips_only_code_files` test body 그대로):
  - 300 KB PDF / 300 KB markdown / 300 KB `big.rs` (3 file) tempdir 합성.
  - `FsSourceConnector` (`max_file_bytes = 262_144`, `max_file_lines = 5_000`) 의 `scan_with_skips(&SourceScope::default())`.
  - assertions:
    - `paths.contains("paper.pdf")` (PDF walker pass).
    - `paths.contains("notes.md")` (Markdown walker pass).
    - `!paths.contains("big.rs")` (code file walker skip).
    - `skips.skip_examples.size_exceeded` 안 `big.rs` 1 entry, `paper.pdf` 0 entry.
  - cfg helper: 기존 test module 의 `cfg_with_size_cap(root, max_bytes, max_lines)` 패턴 재사용 (필요 시 helper 추가).
- **Acceptance**:
  - `cargo test -p kebab-source-fs size_cap_skips_only_code_files -j 4` green.
  - 기존 `ingest_report_counts_oversized_files_by_bytes` (fixture `huge.rs`) + `ingest_report_size_cap_by_line_count` (fixture `longfile.rs`) regression 0 — fixture 명이 `.rs` 라 새 conditional 통과 (invariant preserved).
  - `cargo test -p kebab-source-fs -j 4` 전체 green.

#### Commit (Step 1 전체)

```
fix(source-fs): apply size limit only to code files; PDF/image/markdown bypass walker cap (Bug #2)

- crates/kebab-source-fs/src/code_meta.rs: add pub(crate) fn is_code_file
- crates/kebab-source-fs/src/connector.rs: walker conditional `is_code_file && is_oversized`
- crates/kebab-source-fs/src/connector.rs mod tests: size_cap_skips_only_code_files unit test
- spec: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md §3
```

---

### Step 2 (Group B): Bug #3 chunk_id collision fix + chunker_version bump

spec §4.3 의 Option A (segment boundary `start` 를 `per_chunk_hash` suffix 로). `chunk_page` return tuple 을 3-tuple `(actual_start, chunk_end, slice)` → 4-tuple `(segment_start, actual_start, chunk_end, slice)` 로 확장 + caller `per_chunk_hash` suffix 를 `segment_start` 로 변경. `VERSION_LABEL` `"pdf-page-v1"` → `"pdf-page-v1.1"` bump (spec §4.4.1 round 1c M-1 decision — explicit cascade audit trail).

#### Sub-action B1 — `chunk_page` 4-tuple expansion

- **Files affected**: `crates/kebab-chunk/src/pdf_page_v1.rs:200-204` (doc comment) + `:205-289` (signature line 205 → closing `}` line 289). 본 critic round 1 + verifier round 1 의 actual probe 결과 정정 (L-1).
- **Action** (spec §4.4 diff 그대로):
  - doc comment 갱신 — `(char_start, char_end, text_slice)` → `(segment_start, actual_start, chunk_end, text_slice)`:
    ```rust
    /// Split a single page's text into ordered chunks, each represented as
    /// `(segment_start, actual_start, chunk_end, text_slice)`.
    ///
    /// - `segment_start` = pre-overlap segment boundary. Strictly increasing
    ///   across the returned vec. Use this for chunk_id uniqueness suffixes.
    /// - `actual_start` = post-overlap start char index. May collapse to a
    ///   previous chunk's `actual_start` under aggressive overlap policy.
    ///   Use this for `SourceSpan::Page::char_start`.
    /// - `chunk_end` = chunk's end char index (exclusive).
    fn chunk_page(text: &str, target_bytes: usize, overlap_bytes: usize)
        -> Vec<(usize, usize, usize, String)>
    ```
  - early return: `vec![(0, n, text.to_string())]` → `vec![(0, 0, n, text.to_string())]`.
  - loop body 의 push: `chunks.push((actual_start, chunk_end, slice))` → `chunks.push((start, actual_start, chunk_end, slice))`. (`start = bounds[seg_idx]` 는 이미 local var 로 존재 — line 245.)
  - overlap walk 의 `let prev_min = prev.0` 가 기존 tuple 의 첫 field = post-fix tuple shape 에서는 `prev.1` (actual_start) — spec §4.4 의 invariant 보존 위해 변경:
    ```diff
    -        let actual_start = if let Some(prev) = chunks.last() {
    -            let prev_min = prev.0;
    +        let actual_start = if let Some(prev) = chunks.last() {
    +            // prev tuple shape = (segment_start, actual_start, chunk_end, slice).
    +            // overlap walk floor = previous chunk's actual_start (prev.1).
    +            let prev_min = prev.1;
                ...
    ```
- **Acceptance**:
  - `grep -nE "fn chunk_page.*-> Vec<\(usize, usize, usize, String\)>" crates/kebab-chunk/src/pdf_page_v1.rs` = **1**.
  - `grep -c "let prev_min = prev.1" crates/kebab-chunk/src/pdf_page_v1.rs` ≥ **1**.
  - `cargo build -p kebab-chunk -j 4` green (caller B2 sub-action 동시 적용 후 red 해소).

#### Sub-action B2 — caller `per_chunk_hash` suffix → `segment_start`

- **Files affected**: `crates/kebab-chunk/src/pdf_page_v1.rs:149-186` (현재 verified — `chunk` method 의 `for (...) in chunk_page(...)` loop start line 149 → loop end line 186, verifier round 1 L-2 정정).
- **Action** (spec §4.4 diff 그대로):
  ```diff
  -            for (char_start, char_end, slice) in
  -                chunk_page(&p.text, target_bytes, overlap_bytes)
  +            for (segment_start, char_start, char_end, slice) in
  +                chunk_page(&p.text, target_bytes, overlap_bytes)
               {
                   ...
                   let span = SourceSpan::Page {
                       page: page_num,
                       char_start: Some(char_start_u32),
                       char_end: Some(char_end_u32),
                   };
                   let block_ids: Vec<BlockId> = vec![p.common.block_id.clone()];
  -                // Per-chunk policy_hash variant prevents chunk_id
  -                // collision when a page produces multiple chunks. See
  -                // module docs for rationale.
  -                let per_chunk_hash = format!("{base_policy_hash}#c{char_start}");
  +                // v0.20.0 sub-item 1 bugfix (#3): per-chunk policy_hash
  +                // variant uses `segment_start` (pre-overlap boundary,
  +                // strictly increasing) instead of `char_start` (post-
  +                // overlap, may collapse to prev_min). See module docs +
  +                // spec §4.1 root cause + HOTFIXES.md 2026-05-27.
  +                let per_chunk_hash = format!("{base_policy_hash}#c{segment_start}");
                   let chunk_id =
                       id_for_chunk(&doc.doc_id, &chunker_version, &block_ids, &per_chunk_hash);
                   ...
               }
  ```
  - `SourceSpan::Page.char_start` 는 여전히 post-overlap `char_start` (= `actual_start`) 보존 — citation locality semantic 유지.
- **Acceptance** (verifier round 1 M-2: B2+B4 가 같은 logical commit 안 → grep 시점 = Step 2 commit time, 즉 post-B4):
  - `grep -c "#c{segment_start}" crates/kebab-chunk/src/pdf_page_v1.rs` ≥ **1** (B2 단독 적용 시 = 1 call site; B4 module doc 적용 후 = 2 — B4 acceptance 가 ≥ 2 검증).
  - `grep -c "#c{char_start}" crates/kebab-chunk/src/pdf_page_v1.rs` = **0** (call site + module doc 모두 segment_start 로 교체 — B2+B4 의 same-commit consolidated invariant).
  - sub-action-by-sub-action 분리 검증 시 B2 단독 grep `#c{char_start}` 는 module doc line 56 의 literal 잔존으로 ≥ 1 — Step 2 commit boundary 도달 후 = 0 으로 확정.

#### Sub-action B3 — `VERSION_LABEL` bump `"pdf-page-v1"` → `"pdf-page-v1.1"` + hardcoded literal 2 site 갱신

- **Files affected** (verifier round 1 H-1 의 actual probe `grep -rn '"pdf-page-v1"' crates/ --include='*.rs'` 결과 2 site enumerate):
  - `crates/kebab-chunk/src/pdf_page_v1.rs:67` (현재 verified — `const VERSION_LABEL: &str = "pdf-page-v1";`).
  - `crates/kebab-app/tests/pdf_pipeline.rs:168` (현재 verified — `assert_eq!(pdf_item.chunker_version.as_ref().map(|c| c.0.as_str()), Some("pdf-page-v1"))` hard assertion, v1.1 bump 후 fail).
  - `crates/kebab-app/tests/pdf_pipeline.rs:368` (현재 verified — error message string literal `"pdf-page-v1 emits 0 chunks for the empty page; total = 2"`, hard assertion 아니지만 stale 방지).
- **Action** (spec §4.4.1 결정):
  - **(a) primary const bump** (`crates/kebab-chunk/src/pdf_page_v1.rs:67`):
    ```diff
    -const VERSION_LABEL: &str = "pdf-page-v1";
    +const VERSION_LABEL: &str = "pdf-page-v1.1";
    ```
    기존 test `chunker_version_is_pdf_page_v1` (pdf_page_v1.rs:374) 의 assertion 은 `VERSION_LABEL` const 인용 → 자동 갱신, test code 변경 불요.
  - **(b) test assertion literal 갱신** (`crates/kebab-app/tests/pdf_pipeline.rs:168`, required):
    ```diff
    -        Some("pdf-page-v1")
    +        Some("pdf-page-v1.1")
    ```
  - **(c) test error message literal 갱신** (`crates/kebab-app/tests/pdf_pipeline.rs:368`, recommended):
    ```diff
    -        "pdf-page-v1 emits 0 chunks for the empty page; total = 2"
    +        "pdf-page-v1.1 emits 0 chunks for the empty page; total = 2"
    ```
- **Acceptance**:
  - `grep -nE 'const VERSION_LABEL: &str = "pdf-page-v[0-9.]+";' crates/kebab-chunk/src/pdf_page_v1.rs` 결과 = `"pdf-page-v1.1"`.
  - `cargo test -p kebab-chunk chunker_version_is_pdf_page_v1 -j 4` green (VERSION_LABEL 인용이라 자동 통과).
  - `grep -rn '"pdf-page-v1"' crates/ --include='*.rs' | grep -v 'pdf-page-v1\.1'` = 결과 **0** (regex 의 false-positive 방지 — `pdf-page-v1.1` 의 substring `"pdf-page-v1"` 은 ".1" suffix 로 exclude). `grep -v` filter 후 line 0 이면 stale literal 잔존 0.
  - `cargo test -p kebab-app pdf_pipeline -j 4` green (line 168 assertion 갱신 후).

#### Sub-action B4 — module doc 갱신 + HOTFIXES.md entry

- **Files affected**:
  - `crates/kebab-chunk/src/pdf_page_v1.rs:47-60` (현재 verified — module doc `## chunk_id collision deviation` 단락).
  - `tasks/HOTFIXES.md` (new dated entry append, 기존 entry 위치 — file 의 latest entry 가 `2026-05-26` 이므로 그 위에 `2026-05-27 — v0.20.0 sub-item 1` entry insert; 본 file 의 chronological pattern 따름).
- **Action**:
  - **(a) module doc** — spec §4.4 의 갱신본 그대로:
    ```diff
    -//! Workaround that doesn't change the §4.2 recipe: feed a per-chunk
    -//! variant `format!("{base_policy_hash}#c{char_start}")` into the
    -//! recipe's `policy_hash` slot (so distinct chunks distinguish via
    -//! different policy_hash inputs), while storing the unmodified
    -//! `base_policy_hash` in `Chunk.policy_hash` so the field still answers
    -//! "what policy was active". Logged in `tasks/HOTFIXES.md`.
    +//! Workaround that doesn't change the §4.2 recipe: feed a per-chunk
    +//! variant `format!("{base_policy_hash}#c{segment_start}")` into the
    +//! recipe's `policy_hash` slot. `segment_start` is the pre-overlap
    +//! segment boundary, strictly increasing across the returned chunks
    +//! even when the overlap walk collapses `actual_start` to a previous
    +//! chunk's `prev_min`. Unmodified `base_policy_hash` is stored in
    +//! `Chunk.policy_hash` so the field still answers "what policy was
    +//! active". v1.1 second-iteration patch — logged in
    +//! `tasks/HOTFIXES.md` (2026-05-27).
    ```
  - **(b) HOTFIXES.md entry** (spec §4.4 의 entry body 그대로):
    ```markdown
    ## 2026-05-27 — v0.20.0 sub-item 1: chunk_id `#c{char_start}` workaround collapses under aggressive overlap (Bug #3 second-iteration patch)

    **Symptom**: F2 (1580 chars OCR, scanned_page2.pdf) ingest 시
    `DocumentStore::put_chunks (pdf): sqlite error: UNIQUE constraint
    failed: chunks.chunk_id: ... Error code 1555: A PRIMARY KEY constraint
    failed`. `kebab v0.20.0` (commit `b4d9e60`) dogfood (qwen2.5vl:3b 의
    `192.168.0.47:11434` Ollama endpoint, `/build/cache/tmp/v0.20-dogfood`
    isolated KB) `--force-reingest` 마다 reproducible.

    **Root cause**: `crates/kebab-chunk/src/pdf_page_v1.rs:170` 의
    `per_chunk_hash = format!("{base_policy_hash}#c{char_start}")` 에서
    `char_start` = post-overlap `actual_start`. line 266-281 의 overlap
    walk 가 `prev_min` floor 까지만 back-walk 하므로 aggressive overlap
    + 첫 segment 가 작은 page (F2 의 한국어 OCR text: 첫 ~10 char 안
    sentence-end → segment_1 = [0, 30], segment_2 = [30, n], overlap_bytes
    240 / chars=80 → segment_2 의 actual_start 가 prev_min=0 으로
    collapse) → 두 chunk 의 `#c0` suffix identical → identical chunk_id →
    `chunks` PRIMARY KEY violation.

    **Fix** (spec §4.4): `chunk_page` return tuple 에 `segment_start`
    추가 (3-tuple → 4-tuple `(segment_start, actual_start, chunk_end,
    slice)`), caller `per_chunk_hash` 의 suffix 를 `segment_start` 로
    변경. `segment_start` 는 `bounds[seg_idx]` (dedup 후 strictly
    increasing) — overlap walk 와 무관하게 모든 chunk distinct. citation
    locality 의 `SourceSpan::Page.char_start` 는 여전히 post-overlap
    `actual_start` 유지.

    **chunker_version cascade**: `pdf-page-v1` → `pdf-page-v1.1` bump
    (spec §4.4.1 round 1c M-1 결정, design §9 cascade rule 의 직접 적용).
    multi-chunk PDF page (pre-OCR 시점 `metro-korea.pdf` 의 21 block /
    34 chunk 같은 정상 path) 의 chunk_id 가 변경 — explicit user-facing
    audit trail 확보, store layer 의 자동 invalidation report. v0.20.0
    force-update path 라 사용자 cost zero (어차피 fresh ingest).

    **Amends**: spec `docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md`
    §4.4. parent design §4.2 chunk_id recipe 자체 unchanged (workaround
    layer 의 internal computation 만 변경). parent PR #189
    (`feat/pdf-scanned-ocr`, force-update path).
    ```
- **Acceptance**:
  - `grep -c "#c{segment_start}" crates/kebab-chunk/src/pdf_page_v1.rs` ≥ **2** (module doc + line 170 의 actual call).
  - `grep -c "2026-05-27 — v0.20.0 sub-item 1: chunk_id" tasks/HOTFIXES.md` = **1**.

#### Sub-action B5 — unit regression test `multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids`

- **Files affected**: `crates/kebab-chunk/src/pdf_page_v1.rs` 의 `#[cfg(test)] mod tests` (현재 verified — `make_pdf_doc(&[&str])` + `default_policy(target, overlap)` helper 이미 존재, line 300-371).
- **Action** (spec §4.5 의 test body 그대로):
  ```rust
  #[test]
  fn multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids() {
      // 한국어 OCR text 의 trigger shape: 10 char "가" + ". " + 500 char "나".
      // → first segment [0, 12), second segment [12, n).
      //   page_text byte_len = 10*3 + 2 + 500*3 = 1532 > target_bytes=1500
      //   → multi-chunk. overlap_bytes = min(240, 750) = 240 chars=80
      //   → second chunk 의 actual_start 가 prev_min=0 collapse → same `#c0`.
      //
      // default_policy(500, 80) — target_tokens=500 → target_bytes=500*3=1500
      // (한국어 3byte/char 환산), overlap_tokens=80 → overlap_bytes=min(240, 750)=240.
      // verifier round 1 L-3 보강.
      let early_seg: String = std::iter::repeat('가').take(10).collect();
      let tail: String = std::iter::repeat('나').take(500).collect();
      let page_text = format!("{early_seg}. {tail}");

      let doc = make_pdf_doc(&[&page_text]);
      let policy = default_policy(500, 80);  // target=1500 byte, overlap=240 byte
      let chunks = PdfPageV1Chunker.chunk(&doc, &policy).unwrap();

      assert!(
          chunks.len() >= 2,
          "expected ≥2 chunks for {} byte page; got {}",
          page_text.len(),
          chunks.len()
      );

      let mut ids: Vec<&str> = chunks.iter().map(|c| c.chunk_id.0.as_str()).collect();
      ids.sort_unstable();
      let total = ids.len();
      ids.dedup();
      assert_eq!(
          ids.len(),
          total,
          "all chunk_ids must be unique even when overlap walks actual_start back to prev_min"
      );
  }
  ```
- **Acceptance**:
  - `cargo test -p kebab-chunk multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids -j 4` green.
  - `cargo test -p kebab-chunk deterministic_chunk_ids_1000 -j 4` green (기존 determinism invariant 보존).
  - `cargo test -p kebab-chunk overlap_clamped_when_overlap_exceeds_target -j 4` green (기존 overlap clamp invariant 보존).
  - `cargo test -p kebab-chunk -j 4` 전체 green.

#### Commit (Step 2 전체)

```
fix(chunk): chunk_id collision under aggressive overlap; bump pdf-page-v1 → pdf-page-v1.1 (Bug #3)

- crates/kebab-chunk/src/pdf_page_v1.rs: chunk_page returns 4-tuple
  (segment_start, actual_start, chunk_end, slice); caller per_chunk_hash
  suffix uses segment_start (pre-overlap boundary, strictly increasing)
  instead of char_start (post-overlap, may collapse to prev_min).
- VERSION_LABEL "pdf-page-v1" → "pdf-page-v1.1" (design §9 cascade,
  explicit user-facing audit trail).
- module docs: workaround description updated to segment_start.
- mod tests: multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids
  regression pin.
- tasks/HOTFIXES.md: 2026-05-27 entry (symptom F2 1580 char OCR,
  intra-doc collision root cause, second-iteration patch rationale).
- spec: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md §4
```

---

### Step 3 (Group C): Bug #3 multi-scanned PDF integration test

spec §4.5 + §4.5.1 — `kebab-app` integration 수준의 chunk_id collision-free regression. real Ollama 회피 위해 `OcrEngine` trait 의 MockOcrEngine. 기존 `crates/kebab-app/tests/pdf_ocr_apply.rs:20-45` 의 private MockOcrEngine 가 같은 crate 의 별 test binary 라 직접 import 불가 — executor 의 first sub-action 으로 share path 결정.

#### Sub-action C1 — MockOcrEngine share decision (executor 의 dependency 확인 task)

- **Files affected** (Option 별 분기):
  - **Option A (share via `tests/common/`)** — verifier round 1 H-2 의 actual probe 결과 정정:
    - `crates/kebab-app/tests/common/mod.rs` 는 **이미 존재** (172 line `TestEnv` infrastructure, `#![allow(dead_code)]` + `pub struct TestEnv` + `pub fn ingest_md` + `pub fn lexical_query` 등). action = **`pub mod mock_ocr;` 1줄 append** (mod.rs 신규 X).
    - `crates/kebab-app/tests/common/mock_ocr.rs` (**신규** file, MockOcrEngine lift + per-page ctor).
    - 기존 `pdf_ocr_apply.rs:20-45` 의 MockOcrEngine struct + impl 제거 + `mod common; use common::mock_ocr::MockOcrEngine;` import 추가 + ctor call site migration (M-3 참조).
    - 신규 integration test 가 `mod common; use common::mock_ocr::MockOcrEngine;` 으로 share.
  - **Option B (inline 중복)**: 신 test file `multi_scanned_pdf_ingest_no_chunk_id_collision.rs` 안에 inline `struct LocalMockOcr` + `impl OcrEngine for LocalMockOcr` (test isolation 우선, common/mod.rs touch X).
- **Action**:
  - **(a) dependency probe** — spec §4.5.1 의 결정 path 따름:
    ```bash
    grep -rn "impl OcrEngine" crates/kebab-parse-image/src/ crates/kebab-app/tests/
    # 실 결과:
    #   crates/kebab-parse-image/src/ocr.rs:235 — production OllamaVisionOcr.
    #   crates/kebab-app/tests/pdf_ocr_apply.rs:25 — test-only MockOcrEngine.
    ls crates/kebab-app/tests/common/mod.rs
    # 실 결과: -rw-r--r-- ... 172 line (TestEnv infrastructure 이미 존재).
    ```
  - **(b) executor 결정**:
    - 기존 MockOcrEngine 의 ctor 가 `MockOcrEngine { expected_text: String, fail: bool }` — per-page 다른 text 길이 지원 위해 ctor signature 확장 필요 (예: `expected_text: Vec<String>` + internal `Mutex<usize>` cursor). 확장이 trivial + 두 test 가 같은 crate → **Option A 권장**.
    - Option A 시 `pdf_ocr_apply.rs` 의 MockOcrEngine ctor 호출 site (현재 실 verifier probe = **10 instantiation site** at lines 140, 170, 193, 210, 242, 284, 311, 334, 359, 399 — critic round 1 L-2 의 "9 → 10" off-by-1 정정. struct define line 21 제외) 가 새 ctor signature 로 migration — backward-compat 위해 두 ctor (`MockOcrEngine::single(text, fail)` + `MockOcrEngine::per_page(texts, fail)`) 제공. **mechanical migration**: 각 site 의 `MockOcrEngine { expected_text: <text>, fail: <bool> }` → `MockOcrEngine::single(<text>, <bool>)` (10 site × 1 line edit, verifier round 1 M-3 의 actual cost).
    - Option B (inline) 는 sharing 비용 > test 격리 가치 시. 본 plan 의 first preference = Option A.
  - **(c) 결정 결과 record**: result file (`.omc/reviews/2026-05-27-v0.20-bugfix-plan-drafter-r1c-result.md`) 의 closing summary 의 §6 open question 1 에 결정 path 기록 — Option A 시 sub-action C2 의 file edit = (existing) `common/mod.rs` append 1 line + (new) `common/mock_ocr.rs` + (modify) `pdf_ocr_apply.rs` + (new) `multi_scanned_pdf_ingest_no_chunk_id_collision.rs` = 4 file. Option B 시 1 new file 만.
- **Acceptance**:
  - probe grep 결과 ≥ 2 line (production + existing mock).
  - probe ls 결과 — `common/mod.rs` existing 확인.
  - executor 의 결정이 plan 의 §6 open question OQ-1 안에 명시.

#### Sub-action C2 — integration test 작성 (conditional on C1 결정)

- **Files affected** (Option A 채택 가정, verifier round 1 H-2 정정):
  - `crates/kebab-app/tests/common/mod.rs` (**existing** 172 line — `pub mod mock_ocr;` 1줄 append 만).
  - `crates/kebab-app/tests/common/mock_ocr.rs` (**신규** — MockOcrEngine lift + per-page ctor).
  - `crates/kebab-app/tests/pdf_ocr_apply.rs:20-45` (기존 inline impl 제거 + `mod common; use common::mock_ocr::MockOcrEngine;` add — file head 의 mod declaration 1 줄 추가) + ctor call site 10 개 mechanical migration (M-3).
  - `crates/kebab-app/tests/multi_scanned_pdf_ingest_no_chunk_id_collision.rs` (**신규**) — `mod common; use common::mock_ocr::MockOcrEngine;` import.
- **Action** (spec §4.5 의 test body — 본 plan 의 sub-action 안 expanded):
  - **fixture**: F1 (`scanned_page1.pdf`, 779 char OCR) + F2 (`scanned_page2.pdf`, 1580 char OCR) + 1 synthetic small-page PDF (300 char) — 3 scanned PDF.
  - **MockOcrEngine ctor**: per-page text vec `["text for F1", "text for F2 의 1580 char string", "text for synthetic 300 char"]` + `fail: false`.
  - **isolated KB**: `tempfile::tempdir()` + `Config::default()` 의 `data_dir` 만 override + workspace `[ingest.pdf].enabled = true`.
  - **assertion path**:
    1. `kebab_app::ingest_with_config_opts(&cfg, ...)` (facade) 호출.
    2. `report.items.iter().filter(|i| i.kind == IngestItemKind::Error).count() == 0` — chunk_id collision 시 발생할 `ErrorKind::Storage` row 부재.
    3. `store.get_chunks_count() == sum(per-PDF chunk_counts)` — DELETE+INSERT path 의 final row count.
    4. `store.get_all_chunk_ids().iter().collect::<HashSet<_>>().len() == chunks_count` — chunk_id global uniqueness.
  - **executor degradation path** (spec §4.5.1 conditional downgrade): 만약 Option A 의 share 가 비용/위험 크고 Option B 도 비현실적 (예: integration setup 의 ExtractContext / Facade wiring 가 본 sub-action scope 초과) → §6 row 7 의 acceptance 를 conditional downgrade — `kebab-chunk` 의 unit-level invariant (Step 2 B5) 만으로 Bug #3 의 core regression 핀 확보, integration 회피.
- **Acceptance**:
  - `cargo test -p kebab-app multi_scanned_pdf_ingest_no_chunk_id_collision -j 4` green.
  - `cargo test -p kebab-app pdf_ocr_apply -j 4` green (existing test regression 0 — `MockOcrEngine { expected_text, fail }` literal struct construction 10 ctor site 가 `MockOcrEngine::single(text, fail)` 로 migration 후, critic round 1 L-2 actual count).
  - downgrade path 시: result file + commit body 안 "§6 row 7 conditional skip — Bug #3 core regression = kebab-chunk unit B5" 1줄 record.

#### Commit (Step 3 전체)

```
test(app): multi-scanned PDF chunk_id collision-free integration test (Bug #3 regression)

- crates/kebab-app/tests/common/{mod,mock_ocr}.rs: MockOcrEngine lift
  with per-page text ctor (shared by pdf_ocr_apply.rs + new test).
- crates/kebab-app/tests/multi_scanned_pdf_ingest_no_chunk_id_collision.rs:
  3 scanned PDF (F1 + F2 + synthetic 300char) ingest via mock OCR,
  assert all chunk_ids globally unique + zero ErrorKind::Storage rows.
- spec: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md §4.5
```

Option B (inline) 또는 conditional downgrade 채택 시 commit body 와 file list 그에 맞춰 조정.

---

### Step 4 (Group D): Bug #4 F4 fixture re-generation

spec §5 — `tests/fixtures/_synth/mojibake.py` 의 byte-level `re.sub` + 수작업 startxref edit 를 pikepdf 의 proper PDF surgery (open + delete /ToUnicode + save 자동 xref regen) 로 교체. F4 fixture 자체 (`crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf`) regenerate + 3 신규 invariant test.

#### Sub-action D1 — `tests/fixtures/_synth/mojibake.py` pikepdf rewrite

- **Files affected**: `tests/fixtures/_synth/mojibake.py` (전체 rewrite — 기존 byte-edit 패턴 폐기).
- **Action** (spec §5.4 의 body 그대로):
  - Step 1: reportlab 으로 Type 0 (CID) font 사용 한국어 PDF 합성 (정상 ToUnicode CMap 포함).
  - Step 2: pikepdf 로 open + 모든 dictionary 의 `/ToUnicode` entry 제거 + `pdf.save(allow_overwriting_input=True)` (xref 자동 regen).
  - Step 3: invariant 검증 — `len(pdf.pages) == 1` + `b"/ToUnicode" not in dst.read_bytes()`.
  - 실패 시 비-zero exit code + stderr message (Step 2 의 removed count = 0 → exit 2; Step 3 의 page count mismatch → exit 3; ToUnicode 잔존 → exit 4).
- **Dep install** (executor 의 pre-action):
  ```bash
  pip install --cache-dir /build/cache/pip pikepdf reportlab
  python -c "import pikepdf; import reportlab; print(pikepdf.__version__, reportlab.Version)"
  # font availability probe (critic round 1 L-3) — mojibake.py 의 hardcode path.
  test -f /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf \
      || sudo apt-get install -y fonts-dejavu-core
  ```
  CI 환경 미반영 — fixture 자체를 commit 하므로 generation 은 1회성 (Step 4 D2 의 executor local). `tasks/HOTFIXES.md` 에 pikepdf install hint 만 1줄 추가 가능.
- **Acceptance**:
  - `grep -c "import pikepdf" tests/fixtures/_synth/mojibake.py` = **1**.
  - `grep -c "re.sub" tests/fixtures/_synth/mojibake.py` = **0** (byte-edit 패턴 폐기 확인).
  - `test -f /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf` exit 0 (font probe, critic round 1 L-3 fast failover signal).
  - `python tests/fixtures/_synth/mojibake.py /tmp/mojibake_dryrun.pdf && echo OK` exit 0 + stderr 무.

#### Sub-action D2 — F4 fixture binary regenerate + snapshot regen + commit

- **Files affected** (verifier round 1 H-4 + critic round 1 M-2 의 actual probe `grep -rn 'fixtures/mojibake.pdf' crates/` 결과 2 consumer enumerate):
  - `crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf` (regenerate).
  - `crates/kebab-parse-pdf/tests/snapshots/vector_pdf_canonical.json` (**snapshot baseline file 자체** — delete + auto-regen). verifier round 1 H-4 의 actual probe `text_extractor_regression.rs:59-64` 의 hand-rolled `unwrap_or_else { write baseline }` 패턴.
  - `crates/kebab-parse-pdf/tests/text_extractor_regression.rs` (existing test — 코드 자체 변경 0, snapshot regen path 만 trigger).
  - `crates/kebab-parse-pdf/src/text_quality.rs:96` (verifier round 1 H-4 의 2번째 consumer — `let bytes = include_bytes!("../tests/fixtures/mojibake.pdf");` 의 unit test/doctest 가 fixture binary 변경 시 동시 verify, 코드 변경 0).
- **Action**:
  - **(a) regenerate command**:
    ```bash
    python tests/fixtures/_synth/mojibake.py \
        crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf
    ```
  - **(b) regenerate 후 manual probe**:
    ```bash
    python -c "import pikepdf; pdf = pikepdf.open('crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf'); print(len(pdf.pages))"
    # expected: 1
    grep -c "/ToUnicode" crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf
    # expected: 0 (binary grep — Pages dict 안 ToUnicode 부재)
    ```
  - **(c) snapshot baseline regen** (verifier round 1 H-4 + critic round 1 M-2 의 actual mechanic — OQ-2 closure):
    - `text_extractor_regression.rs:59-64` 는 `let baseline = std::fs::read_to_string("tests/snapshots/vector_pdf_canonical.json").unwrap_or_else(|_| { std::fs::write(baseline_path, &actual).expect(...); actual.clone() })` 의 hand-rolled pattern (insta crate 사용 X).
    - fixture binary 변경 → 다음 cargo test 시 `actual != baseline` → `assert_eq!` fail.
    - executor 의 regen step:
      ```bash
      rm crates/kebab-parse-pdf/tests/snapshots/vector_pdf_canonical.json
      cargo test -p kebab-parse-pdf vector_pdf_extract_byte_identical_to_baseline -j 4
      # 1st run: snapshot file 부재 → unwrap_or_else write 패턴이 새 baseline 작성 → assert pass.
      cargo test -p kebab-parse-pdf vector_pdf_extract_byte_identical_to_baseline -j 4
      # 2nd run: 새 baseline 와 byte-identical → assert pass (regression invariant 확립).
      ```
    - OQ-2 closure — insta crate 미사용, cargo-insta CLI 불요. spec §5.6 의 "기존 `text_extractor_regression.rs` 의 F4 baseline 갱신" 의 actual mechanic 명문화.
- **Acceptance**:
  - `stat crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf` size > 0.
  - `grep -c "/ToUnicode" crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf` = **0**.
  - python 의 page count probe = `1`.
  - `test -f crates/kebab-parse-pdf/tests/snapshots/vector_pdf_canonical.json` exit 0 (snapshot regen 후).
  - `cargo test -p kebab-parse-pdf vector_pdf_extract_byte_identical_to_baseline -j 4` 2회 연속 green (regen + verify, H-4 mechanic).
  - `cargo test -p kebab-parse-pdf -j 4` 전체 green — D3 의 신규 test + text_quality.rs:96 의 2번째 consumer 도 동시 verify.

#### Sub-action D3 — parse-pdf 의 3 신규 invariant test

- **Files affected** (verifier round 1 H-3 의 actual probe 결과 결정):
  - actual `ls crates/kebab-parse-pdf/tests/` 결과: `common`, `extractor.rs`, `fixtures`, `ocr_e2e.rs`, `page_image.rs`, `snapshots`, `text_extractor_regression.rs` — plan round 0 의 primary candidate `text_extractor.rs` 는 **존재 안 함**.
  - **결정**: `crates/kebab-parse-pdf/tests/text_extractor_regression.rs` append (F4 fixture consumer locality + D2 snapshot regen mechanic 와 same file). 3 신규 `#[test] fn` append.
  - 대안 (executor 가 file size / cohesion 고려해 split 결정 시): 신규 `crates/kebab-parse-pdf/tests/mojibake_invariants.rs`. plan first preference = append to `text_extractor_regression.rs`.
- **Action** (spec §5.5 의 3 test body 의 path 정정 — verifier round 1 H-3):
  1. `mojibake_fixture_load_yields_one_page` — `let bytes = include_bytes!("fixtures/mojibake.pdf");` (integration test 는 이미 `crates/kebab-parse-pdf/tests/` root, `text_extractor_regression.rs:42` 의 canonical pattern 따름; spec §5.5 의 `"../tests/fixtures/mojibake.pdf"` 가 잘못 — `"fixtures/mojibake.pdf"` 직접). `lopdf::Document::load_mem(bytes).unwrap().get_pages().len() == 1`.
  2. `mojibake_fixture_has_no_tounicode_cmap` — CWD-relative `std::fs::read("tests/fixtures/mojibake.pdf")` 위험 회피 (cargo test 의 CARGO_MANIFEST_DIR ≠ CWD 환경 가능): `let bytes = include_bytes!("fixtures/mojibake.pdf");` 사용. `bytes.windows(b"/ToUnicode".len()).filter(|w| *w == b"/ToUnicode").count() == 0`.
  3. `pdf_text_extractor_on_mojibake_yields_one_block` — `let bytes = include_bytes!("fixtures/mojibake.pdf");` + PdfTextExtractor 의 `1 Block::Paragraph per page` invariant 검증, `canonical.blocks.len() == 1`, `scanned candidate` warning 또는 non-empty text. ExtractContext setup 의 actual body 는 executor 가 `text_extractor_regression.rs` 의 existing helper (있을 시) 또는 spec §5.5 의 placeholder 의 expansion.
- **Acceptance**:
  - `cargo test -p kebab-parse-pdf mojibake_fixture_load_yields_one_page -j 4` green.
  - `cargo test -p kebab-parse-pdf mojibake_fixture_has_no_tounicode_cmap -j 4` green.
  - `cargo test -p kebab-parse-pdf pdf_text_extractor_on_mojibake_yields_one_block -j 4` green.
  - `cargo test -p kebab-parse-pdf -j 4` 전체 green.

#### Commit (Step 4 전체)

```
fix(parse-pdf): F4 mojibake.pdf via pikepdf surgery; preserve 1-page invariant (Bug #4)

- tests/fixtures/_synth/mojibake.py: full rewrite — replace byte-level
  re.sub + manual startxref edit with pikepdf open+del+save (auto xref
  regen). Type 0 font + ToUnicode strip via dictionary walk.
- crates/kebab-parse-pdf/tests/fixtures/mojibake.pdf: regenerate.
- crates/kebab-parse-pdf/tests/text_extractor_regression.rs: append 3
  invariant tests (lopdf 1-page / no ToUnicode marker / PdfTextExtractor
  1-block) — verifier round 1 H-3 의 file path decision (same locality
  with snapshot regen).
- crates/kebab-parse-pdf/tests/snapshots/vector_pdf_canonical.json:
  delete + auto-regen via 2-run cargo test (hand-rolled unwrap_or_else
  pattern, verifier round 1 H-4).
- spec: docs/superpowers/specs/2026-05-27-v0.20-sub1-bugfix-spec.md §5
```

verifier round 1 NIT-2 정정 — commit scope `test-fixture` → `parse-pdf` (crate name, conventional commit typical scope).

---

### Step 5 (Group E): Workspace verify + commit + PR #189 force-push

spec §6 의 16-row consolidated acceptance 를 본 step 의 verifier checklist. 모든 acceptance command 가 scriptable.

#### Sub-action E1 — cargo workspace test `-j 1`

- **Files affected**: 변경 0 (verification only).
- **Action**:
  - **(a) conditional cargo clean** — memory `feedback_cargo_clean_policy` (verifier round 1 NIT-1 정정: TB vs GB unit 혼동 회피 위해 `-BG` 으로 GB unit 강제):
    ```bash
    # /build avail 을 GB 단위 정수로 직접 가져옴 (df -BG output 의 'G' suffix 만 strip).
    AVAIL_GB=$(df -BG --output=avail /build | tail -1 | tr -d ' G')
    # CARGO_TARGET_DIR 의 size 도 GB 단위 정수로 (du -BG output).
    TARGET_GB=$(du -BG -s "${CARGO_TARGET_DIR:-target}" 2>/dev/null | awk '{print $1}' | tr -d 'G')
    # /build avail < 500 GB OR target > 200 GB → clean
    if [[ "${AVAIL_GB:-9999}" -lt 500 ]] || [[ "${TARGET_GB:-0}" -gt 200 ]]; then
        cargo clean
    fi
    ```
    임계 미달 시 skip + commit body / result file 안 1줄 record (예: "skipped cargo clean — /build avail ${AVAIL_GB}G, target ${TARGET_GB}G").
  - **(b) workspace test**:
    ```bash
    cargo test --workspace --no-fail-fast -j 1 2>&1 | tail -100
    ```
  - tail 100 line + final summary "test result: ok. N passed; 0 failed" 확인.
- **Acceptance**:
  - exit code 0.
  - stdout 의 "test result: ok" + "0 failed".
  - spec §6 row 14 (workspace full test pass) 충족.

#### Sub-action E2 — `cargo clippy --workspace -- -D warnings`

- **Files affected**: 변경 0.
- **Action**:
  ```bash
  cargo clippy --workspace --all-targets -j 1 -- -D warnings 2>&1 | tail -50
  ```
- **Acceptance**:
  - exit code 0.
  - "warning" 키워드 0 (or `-D warnings` 가 자동 error 화).
  - spec §6 row 13 (workspace clippy clean) 충족.

#### Sub-action E3 — dogfood re-run (Ollama qwen2.5vl:3b 환경)

- **Files affected**: 변경 0. `/build/cache/tmp/v0.20-dogfood/` (isolated KB, 동일 dogfood 재사용).
- **Action** (memory `feedback_pr_workflow` + `_external/` invariant 따름):
  - **(a) release build**:
    ```bash
    cargo build --release -p kebab-cli -j 4 2>&1 | tail -10
    "${CARGO_TARGET_DIR:-target}/release/kebab" --version
    # expected: kebab 0.20.0
    ```
  - **(b) dogfood KB clean + re-ingest 9 PDF** (spec §1.1 의 dogfood 환경 동일).

    canonical config path = `/build/cache/tmp/v0.20-dogfood/config.toml` (§0 가정). 외부 backup file `/build/cache/tmp/v0.20-dogfood-config.toml` 은 **존재 안 함** — critic round 1 H-1 의 actual probe 결과. 따라서 config 의 **자체 backup 후 clean + restore** path 사용 (destructive `rm -rf` 시 config 동시 삭제 방지):

    ```bash
    # Step A: config 의 임시 backup (KB clean 전 보존).
    cp /build/cache/tmp/v0.20-dogfood/config.toml \
        /build/cache/tmp/v0.20-dogfood-config.toml.bak

    # Step B: KB 전체 clean (config 포함 destructive — backup 으로 보존됨).
    rm -rf /build/cache/tmp/v0.20-dogfood/
    mkdir -p /build/cache/tmp/v0.20-dogfood/

    # Step C: backup 에서 config restore.
    cp /build/cache/tmp/v0.20-dogfood-config.toml.bak \
        /build/cache/tmp/v0.20-dogfood/config.toml

    # config.toml 안 [ingest.pdf].enabled = true, ollama endpoint =
    # http://192.168.0.47:11434, ocr_model = qwen2.5vl:3b

    # Step D: ingest.
    "$RELEASE_BIN" ingest --config /build/cache/tmp/v0.20-dogfood/config.toml \
        --json --force-reingest 2>&1 | tee /build/cache/tmp/v0.20-dogfood-ingest.ndjson

    # Step E (optional): backup file cleanup. 다음 dogfood iteration 의 redundant
    # backup 누적 방지. config 자체는 v0.20-dogfood/config.toml 가 in-place
    # canonical, .bak 은 transient.
    rm /build/cache/tmp/v0.20-dogfood-config.toml.bak
    ```

    (대안 selective-delete 의 single-step path — config 보존 + 그 외 destructive):
    ```bash
    find /build/cache/tmp/v0.20-dogfood/ -mindepth 1 -not -name 'config.toml' \
        -exec rm -rf {} +
    ```
    실 procedure 는 plain 5-step 의 명료성 우선 (executor 의 default).
  - **(c) acceptance**:
    - spec §6 row 3: 9 PDF 의 `skipped_size_exceeded == 0` for non-code (= 모두 0 — workspace 가 code 0).
    - spec §6 row 8: F1 + F2 의 `kind != "Error"` (chunk_id collision 부재).
    - spec §6 row 12: mojibake.pdf 의 ingest item `block_count: 1`.
    - spec §6 row 15: 9 PDF 모두 ingest, `errors = 2` (encrypted only — pre-existing dogfood baseline 동일).
  - **Ollama 미가용 시 fallback**: endpoint 가 unreachable 면 본 sub-action 의 partial skip 가능 — workspace test (E1) + clippy (E2) 의 unit/integration 수준 evidence 로 spec §6 row 1, 2, 4-7, 9-11, 13-14, 16 충족 + dogfood row 3, 8, 12, 15 skip 1줄 record (commit body + result file).
- **Acceptance**:
  - ingest report 의 ndjson 안 errors = 2 (encrypted only).
  - F1/F2/mojibake 각각의 item line `kind` field 가 success path (= `"new"` 또는 `"unchanged"`, not `"Error"`).
  - dogfood log path: `/build/cache/tmp/v0.20-dogfood-ingest.ndjson` (commit body 안 reference).

#### Sub-action E4 — commit 점검 + 최종 organize

- **Files affected**: 모든 step 의 누적 changes.
- **Action**:
  - `git status` + `git log --oneline b4d9e60..HEAD` — Step 1-4 의 4 commit + Step 5 의 verify-only commit 0 (verification 만, commit 없음).
  - 만약 work-in-progress 잔존 file 있으면 reset.
  - commit message 의 `Co-Authored-By:` line 점검 (CLAUDE.md gitea-pr workflow).
- **Acceptance**:
  - `git log --oneline b4d9e60..HEAD | wc -l` = **4** (Step 1-4 의 각 1 commit).
  - `git status` 의 untracked + modified = 0.

#### Sub-action E5 — PR #189 force-push

- **Files affected**: remote ref `gitea/feat/pdf-scanned-ocr`.
- **Action** (gitea-ops skill 의 직접 호출 가능):
  ```bash
  git push gitea feat/pdf-scanned-ocr --force-with-lease
  ```
  - `--force-with-lease` — local 의 fetch state 와 remote HEAD 가 match 시에만 force-push (다른 collaborator 의 push 보호; 본 single-user 환경 cheap safety).
  - PR #189 의 body 갱신 — Bug #2/#3/#4 fix summary + dogfood evidence 추가 (gitea API `PATCH /repos/altair823-org/kebab/pulls/189`).
  - 사용자 memory `feedback_pr_workflow` 따라 `gitea-pr-review` skill 의 review 루프 진입 (multi-round critic + verifier).
- **Acceptance**:
  - `gh-equivalent` (gitea-ops `gitea-pr-status 189`) 의 head SHA = local `git rev-parse HEAD`.
  - PR #189 의 commit count = 이전 force-push 시점 의 commit count + 4.
  - sequencing summary 의 5-commit table (§7) 와 final state 일치.

#### Commit (Step 5)

verification only — git commit 0. Step 1-4 의 4 commit 가 final tree.

---

## §4 Verifier checklist (spec §6 16-row 1:1 mapping)

각 row 가 scriptable command. step 5 E1-E3 의 누적 실행으로 모두 가능.

| # | Verifier | Bug | step | 명령 |
|---|---------|-----|------|------|
| 1 | walker bypasses size cap for PDF | #2 | A3 | `cargo test -p kebab-source-fs size_cap_skips_only_code_files -j 4` |
| 2 | walker still skips oversized code files | #2 | A3 | `cargo test -p kebab-source-fs ingest_report_counts_oversized_files_by_bytes -j 4` |
| 3 | 256KB+ PDF/markdown ingest default config | #2 | E3 | dogfood: `$RELEASE_BIN ingest ...` 의 ingest report 의 `skipped_size_exceeded = 0` for non-code |
| 4 | chunker collision regression test | #3 | B5 | `cargo test -p kebab-chunk multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids -j 4` |
| 5 | chunker determinism preserved | #3 | B5 | `cargo test -p kebab-chunk deterministic_chunk_ids_1000 -j 4` |
| 6 | chunker overlap clamp preserved | #3 | B5 | `cargo test -p kebab-chunk overlap_clamped_when_overlap_exceeds_target -j 4` |
| 7 | integration: multi-scanned PDF ingest (conditional, §4.5.1) | #3 | C2 | `cargo test -p kebab-app multi_scanned_pdf_ingest_no_chunk_id_collision -j 4` (Option A/B downgrade path 시 skip + record) |
| 8 | dogfood: F1 + F2 force-reingest errors=0 | #3 | E3 | dogfood: `$RELEASE_BIN ingest --force-reingest ...` 의 errors = 0 (encrypted 제외) |
| 9 | F4 fixture lopdf 1-page invariant | #4 | D3 | `cargo test -p kebab-parse-pdf mojibake_fixture_load_yields_one_page -j 4` |
| 10 | F4 fixture ToUnicode 부재 invariant | #4 | D3 | `cargo test -p kebab-parse-pdf mojibake_fixture_has_no_tounicode_cmap -j 4` |
| 11 | F4 PdfTextExtractor 1-block invariant | #4 | D3 | `cargo test -p kebab-parse-pdf pdf_text_extractor_on_mojibake_yields_one_block -j 4` |
| 12 | dogfood: F4 ingest block_count=1 | #4 | E3 | dogfood: mojibake.pdf 의 ingest item `block_count: 1` |
| 13 | workspace clippy clean | all | E2 | `cargo clippy --workspace --all-targets -j 1 -- -D warnings` |
| 14 | workspace full test pass | all | E1 | `cargo test --workspace --no-fail-fast -j 1` |
| 15 | dogfood end-to-end 9 PDF | all | E3 | dogfood: 9 PDF 모두 ingest, errors = 2 (encrypted only) |
| 16 | chunker_version cascade final value | #3 | B3 | `grep -nE 'pdf-page-v[0-9.]+' crates/kebab-chunk/src/pdf_page_v1.rs` 결과가 `"pdf-page-v1.1"` |

executor 의 final step (E1-E3) 에서 16 row 모두 scriptable 실행 + result file 안 row-by-row pass/fail/skip 기록.

#### Workspace baseline expected test count delta (verifier round 1 M-1 closure)

`cargo test --workspace -j 1` (Step 5 E1) 의 expected `test result: ok. N passed` 의 delta 산수 — pre-fix baseline 대비:

| Step | Sub-action | new test name | crate | type |
|---|---|---|---|---|
| 1 | A3 | `size_cap_skips_only_code_files` | kebab-source-fs | unit (in `mod tests`) |
| 2 | B5 | `multi_chunk_page_with_aggressive_overlap_produces_unique_chunk_ids` | kebab-chunk | unit (in `mod tests`) |
| 3 | C2 | `multi_scanned_pdf_ingest_no_chunk_id_collision` | kebab-app | integration (new test binary) |
| 4 | D3 | `mojibake_fixture_load_yields_one_page` | kebab-parse-pdf | unit-style integration |
| 4 | D3 | `mojibake_fixture_has_no_tounicode_cmap` | kebab-parse-pdf | unit-style integration |
| 4 | D3 | `pdf_text_extractor_on_mojibake_yields_one_block` | kebab-parse-pdf | unit-style integration |

- **Option A (full path, C2 active)**: total = **+6 unit/integration test cases + 1 new integration test binary**.
- **Option B (C2 conditional downgrade per §4.5.1)**: total = **+5 test cases + 0 new binary**.

기타: B3 의 `chunker_version_is_pdf_page_v1` 기존 test 의 assertion content 변경 없음 (VERSION_LABEL const 인용) → test count delta 0. D2 의 `vector_pdf_extract_byte_identical_to_baseline` 기존 test 의 assertion 결과만 변경 (fixture 변경 → baseline 변경) → test count delta 0, snapshot regen action 만 추가.

executor 가 E1 acceptance 의 N 비교 시 본 delta 산수 와 일치 확인 (regression 시 detection).

---

## §5 Risks (plan 단계)

- **R-1 (MockOcrEngine sharing complexity)**: spec §4.5.1 의 Option A (`tests/common/mock_ocr.rs` lift) 가 기존 `pdf_ocr_apply.rs:20-45` 의 9 test 의 ctor migration 필요 — backward-compat ctor 2 개 (single + per_page) 도입 시 trivial, 실패 시 Option B (inline) downgrade. spec §6 row 7 conditional skip 가능.
- **R-2 (chunker_version bump cascade scope)**: `pdf-page-v1.1` 의 영향 = multi-chunk PDF page 의 chunk_id 변경. parser_version / embedding_version / prompt_template_version / index_version unchanged — `kebab-eval::eval_runs.config_snapshot_json` 의 5-version snapshot 의 chunker_version field 만 새 값. parent design §9 의 cascade rule invariant 보존, eval baseline 의 re-run 권장 (spec §7.1 Risk 1 의 user-facing note).
- **R-3 (F4 fixture binary churn)**: pikepdf 의 save output 가 reportlab+byte-edit 와 다른 PDF object ordering → SHA256 변경 + git binary diff noise. `text_extractor_regression.rs` baseline 도 새 fixture 의 actual output 으로 same-commit update — Step 4 D2 안 동시 처리.
- **R-4 (dogfood Ollama 의존)**: spec §6 row 3 + 8 + 12 + 15 dogfood acceptance 가 real `192.168.0.47:11434` qwen2.5vl:3b 호출. endpoint 미가용 시 unit/integration evidence (row 1-2, 4-7, 9-11, 13-14, 16) 로 partial closure + commit body / result file 안 skip record.
- **R-5 (pikepdf dependency install)**: Step 4 D1 의 mojibake.py 의 `import pikepdf` — 본 머신의 Python venv 에 pip install 필요. CI 의존성 미발생 (fixture commit 후 1회성 generation).
- **R-6 (parent plan 와의 동시 진행 충돌 0 확인)**: parent plan (`2026-05-27-pdf-scanned-ocr-plan.md` round 1c ACCEPT) 의 Step 11 (final verify + PR open) 가 이미 commit `b4d9e60` 으로 closed. 본 plan 의 fix commits 가 그 commit 위에 stack — branch ordering 충돌 0.

---

## §6 Open questions deferred to executor

- **OQ-1 (MockOcrEngine sharing path)**: spec §4.5.1 의 Option A (`tests/common/mock_ocr.rs` lift) vs Option B (inline) 결정. executor 의 Step 3 C1 안 first action — probe `grep -rn "impl OcrEngine"` 후 결정 + result file 안 record. plan first preference = Option A.
- **OQ-2 (F4 baseline snapshot update tool)**: ✅ **CLOSED (round 1c, critic M-2 + verifier H-4)** — `text_extractor_regression.rs:59-64` 의 actual pattern = hand-rolled `unwrap_or_else { write baseline }` (insta crate 사용 X). regen procedure = snapshot file `tests/snapshots/vector_pdf_canonical.json` 삭제 + cargo test 2회 (1st auto-regen, 2nd verify). cargo-insta CLI 불요. detail = §3 Step 4 D2 의 Action (c).
- **OQ-3 (pikepdf install command)**: `pip install` 의 cache-dir + venv 결정 — global `--user` pip 또는 fixture generation 전용 venv 또는 conda environment. plan 의 default = `pip install --cache-dir /build/cache/pip pikepdf reportlab` (memory `feedback_disk_layout`).
- **OQ-4 (dogfood config.toml 의 endpoint 변경 시점)**: 본 dogfood 환경의 `192.168.0.47:11434` Ollama endpoint 가 변경되면 executor 가 alternative endpoint (`localhost:11434` 등) 로 override + result file 안 record.
- **OQ-5 (PR #189 review 루프의 round 수)**: memory `feedback_pr_workflow` 의 gitea-pr + 리뷰 루프 — round 1 critic + verifier 의 결과에 따라 round 2/2c 진입 가능. 본 plan 은 round 0 (drafter) — review round 의 outcome 은 plan 외 scope.

---

## §7 Sequencing summary (logical commit boundaries)

| commit # | step range | logical scope | file count |
|---:|---|---|---:|
| 1 | Step 1 (A1+A2+A3) | `fix(source-fs): apply size limit only to code files; PDF/image/markdown bypass walker cap (Bug #2)` | 2 |
| 2 | Step 2 (B1+B2+B3+B4+B5) | `fix(chunk): chunk_id collision under aggressive overlap; bump pdf-page-v1 → pdf-page-v1.1 (Bug #3)` | 4 (pdf_page_v1.rs + HOTFIXES.md + pdf_pipeline.rs:168 + :368, verifier H-1) |
| 3 | Step 3 (C1+C2) | `test(app): multi-scanned PDF chunk_id collision-free integration test (Bug #3 regression)` | **4 (Option A: existing common/mod.rs append + new common/mock_ocr.rs + modify pdf_ocr_apply.rs + new multi_scanned_pdf_ingest_no_chunk_id_collision.rs, verifier H-2)** / 1 (Option B) |
| 4 | Step 4 (D1+D2+D3) | `fix(parse-pdf): F4 mojibake.pdf via pikepdf surgery; preserve 1-page invariant (Bug #4)` | **5 (mojibake.py + fixtures/mojibake.pdf + snapshots/vector_pdf_canonical.json + text_extractor_regression.rs (D3 append) + src/text_quality.rs:96 consumer verify, verifier H-4 + H-3 + NIT-2)** |
| 5 | Step 5 (E1-E5) | verification only — git commit 0; final state = commits 1-4 위 PR #189 force-push | 0 |

총 4 commit + 1 verify-only step. force-push 후 PR #189 의 head = local HEAD.

---

## §8 Round 1c rewrite changelog (drafter trace)

round 1 critic + verifier 의 합산 21 finding (critic 7 + verifier 14) 적용. detail 은 result file (`.omc/reviews/2026-05-27-v0.20-bugfix-plan-drafter-r1c-result.md`) 의 §1 traceability matrix 참조. 본 §8 은 plan body 의 substantive change summary.

### Critic r1 (7 finding)

| ID | Severity | Action | Plan section |
|---|---|---|---|
| critic H-1 | HIGH | E3 dogfood config 의 backup 후 clean + restore 5-step procedure (외부 backup file 부재 reality 반영) | §3 Step 5 E3 (b) |
| critic M-1 | MEDIUM | line 15 "17 sub-action" → "18 sub-action" | §0 prelude line |
| critic M-2 | MEDIUM | D2 snapshot baseline 갱신 mechanic 명문 (hand-rolled `unwrap_or_else` pattern, OQ-2 closure) | §3 Step 4 D2 + §6 OQ-2 |
| critic L-1 | LOW | B1 line range "200-289" → "200-204 (doc) + 205-289 (body)" 명시 | §3 Step 2 B1 |
| critic L-2 | LOW | MockOcrEngine ctor count "9 test (existing)" → "10 instantiation site" (actual probe) | §3 Step 3 C1 + C2 |
| critic L-3 | LOW | D1 pre-action 에 DejaVuSans.ttf existence probe 1줄 추가 | §3 Step 4 D1 |
| critic NIT-1 | NIT | "5 logical commit" → "4 commit + 1 verify-only step (= 5 step total, 4 commit boundary)" | §0 prelude line |

### Verifier r1 (14 finding)

| ID | Severity | Action | Plan section |
|---|---|---|---|
| verifier H-1 | HIGH | B3 sub-action 에 `pdf_pipeline.rs:168` (hard assertion) + `:368` (error message) literal 갱신 명시 + acceptance grep regex 정밀화 (`grep -v 'pdf-page-v1\.1'`) | §3 Step 2 B3 |
| verifier H-2 | HIGH | Step 3 Option A 의 `common/mod.rs` 가 existing infrastructure 반영 — `pub mod mock_ocr;` 1줄 append + 신규 `common/mock_ocr.rs` + `pdf_ocr_apply.rs` lift + 신규 integration test = 4 file edit | §3 Step 3 C1 + C2 + §7 commit 3 file count |
| verifier H-3 | HIGH | D3 file path `text_extractor.rs` 부재 정정 → `text_extractor_regression.rs` append (locality with D2 snapshot regen). `include_bytes!` path 도 `../tests/fixtures/...` → `fixtures/...` 직접 + CWD-relative `std::fs::read` 회피 | §3 Step 4 D3 |
| verifier H-4 | HIGH | D2 snapshot regen mechanic — snapshot file `tests/snapshots/vector_pdf_canonical.json` 삭제 + cargo test 2회 (1st auto-regen, 2nd verify) + `src/text_quality.rs:96` 2번째 consumer enumerate | §3 Step 4 D2 + §7 commit 4 file count |
| verifier M-1 | MEDIUM | §4 verifier checklist 뒤에 expected workspace test count delta 산수 표 추가 (+6 unit + 1 integration, Option A / +5 + 0, Option B) | §4 (sub-section) |
| verifier M-2 | MEDIUM | B2 acceptance phrasing 갱신 — "Step 2 commit time" 명시 + sub-action 별 grep 시점 명문 | §3 Step 2 B2 acceptance |
| verifier M-3 | MEDIUM | C2 Option A 의 "기존 10 ctor site mechanical migration" 명령 명시 | §3 Step 3 C1 (b) |
| verifier L-1 | LOW | pdf_page_v1.rs line range 200-289 → 205-289 (critic L-1 와 same edit pass) | §3 Step 2 B1 |
| verifier L-2 | LOW | caller line range 155-185 → 149-186 | §3 Step 2 B2 |
| verifier L-3 | LOW | B5 test scenario comment 의 target=1500 byte + overlap=240 byte 산수 보강 | §3 Step 2 B5 |
| verifier L-4 | LOW | `ingest_pdf_ocr_smoke.rs` 의 grep B3 scope safety 확인 (별도 action 0, finding 자체 = no action) | (verified safe) |
| verifier NIT-1 | NIT | E1 의 `df -h` unit 처리 산수 정밀화 → `df -BG --output=avail` 으로 GB unit 강제 | §3 Step 5 E1 (a) |
| verifier NIT-2 | NIT | Step 4 commit scope `test-fixture` → `parse-pdf` (crate name) | §3 Step 4 commit |
| verifier NIT-3 | NIT | dogfood config canonical path 의 single-definition (in §0) + 모든 acceptance command 참조 | §0 pre-flight + §3 Step 5 E3 |

### Summary

- frontmatter `status` `draft (round 0)` → `draft (round 1c)`.
- frontmatter `review_history` 에 round 1 critic + verifier + round 1c rewrite 항목 3 줄 add.
- plan body line 15 의 prelude statement 2 token 정정 (sub-action count + commit boundary 표현).
- §0 pre-flight 에 dogfood KB layout 가정 1 bullet add.
- §3 5 step 의 sub-action body 의 detail 보강 (file path / acceptance grep / mechanic / migration cost).
- §4 verifier checklist 의 expected test count delta sub-section add.
- §6 OQ-2 closure 표시 (✅ CLOSED).
- §7 sequencing summary 의 file count 갱신 (commit 2: 2→4, commit 3: 3-4→4, commit 4: 3-4→5).
- §8 round 1c rewrite changelog (본 단락) populate.

총 plan body line 변경 = ~+250 net add (round 0 698 line → round 1c ~950 line).
