feat(cli,propose): reach the arms from okf build, keep a sheet heading behind a flag, fix two PDF contents mechanisms

K3 round 2, per file type. Order 20260908T143513Z-6327528123-from-.claude, carrying two operator decisions taken beforehand: D1 the orphan-gate variant goes behind a flag, D2 the arms become reachable from `okf build`. No default moved. Report: docs/2026-09-08-k3-runde2-per-filtype.md.

THE REPRODUCTION HELD, all three numbers, before any edit: `okf build` on the five-document tender folder gives 31 markdown files with both PDFs flat and 5/5 merged; the tender PDF gives no boundary without a flag and 9 with `--outline-run 3` (reference 9); the price sheet gives 1 on HEAD. Both proposer runs had to go through `bash -c` -- zsh does not word-split an unquoted `$flags`, so a sweep hands `--outline-run 3` to argparse as one token and every row comes back exit 2.

D2 -- `cli.py:_propose_plans` called the proposer with no arm argument, so the build path ran Arm B while `tools/okf_propose_segments.py` could run D, E and F. It now passes `--outline-run`, `--table-grid`, `--unit-fold` and `--keep-table-heading` through unchanged. THE DEFAULT DOES NOT MOVE and that is measured, not asserted: same folder, no flags, before and after the change, digest 3af10770...8fbbe2 both times and `diff -rq` clean. The "before" bundle was built before the first edit, because the editable install reads src/ live. Red test on the PLANS and on titles rather than a count, with the same fixture and no flags as its control. Per-document table for B/D/E/F/F2 is in the README and the report; the tender PDF is 1 under the default and 9 under every arm above it, and the reference is 9.

D1 -- a sheet heading with a table opening under it has an empty body, so the orphan check drops it: the NAME survives (carried onto the table block), the LINE does not. `--keep-table-heading` lets the heading survive and absorb the table instead. Price sheet 1 -> 1 concepts, `source_offset` [34, 11048] -> [0, 11048], body now starting at the heading. ELEVEN IS NOT REACHABLE THIS WAY and the number says why: the sheet is one heading and one continuous pipe-table block, and the eleven cost groups are eleven ROWS inside it (lines 10-20 of 103). What is missing is a section-row rule inside a sheet -- the opposite of `--table-grid`. Corpus: the flag changes 2 of 39 documents, both `.xlsx`, under arms B, E and F alike; known-negative 0 of 32 `pdf` and 0 of 5 `docx`. With it off, Arm E over all 43 is byte-identical to session 109's tree (33 plans, 43 `.err`, 4 FAILED, diff exit 0, counts asserted first).

THE PDF REMAINDER, one at a time. Position 9: clause 1 read the list AFTER the orphan check, and a contents list without dot leaders is a run of bodiless headings, so all but the last entry were already gone and the run was one. The run is now measured on the pre-orphan list, predicate written once and read in both places. 11 -> 10. Position 7: the same clause required siblings, and a numbered report's contents list interleaves 1.1/1.1.1/2.1 -- its 34 entries are one block that the level condition cut into runs of 9, 1, 1, 1, 5, 2, 10, 2 and 3, so the short runs survived. The level condition is dropped; the run LENGTH, which is what the CONTENTS_RUN sweep bought, is unchanged. Measured outward: the relaxation changes 1 document of 39 and removes exactly the leftover line. 34 -> 33.

TWO REMAINDERS ARE DECLINED WITH NUMBERS RATHER THAN FIXED. Position 1: the three level-1 candidates are 3 of 3 `rule:outline`, same level, same grammar, and the operator keeps one of them by prose alone -- there is no property to read. Position 4: a title-length rule was measured on paper and falsified -- a real chapter is 56 characters and a real heading in a document the arms already score correct is 88, sitting between position 4's 86 and 91, so no threshold separates the classes. Position 0 stays an extraction failure.

ONE SHIPPED EXPECTATION MOVED and is stated rather than quietly updated: `Innhold 1` is now discarded with the contents list it heads. Its body is in no segment afterwards, which is a real cost on a fixture where that heading has one.

Nine new tests: five red before the implementation, four green by construction and named as such. Three mutations, three red, unmutated control green each time -- restoring the level condition, computing the run post-orphan, absorbing a table unconditionally. 1379 -> 1388 tests. ruff clean, mypy --strict clean on 17 files. K2 bundle untouched (1108 files, 9cd74519...). The K2 ranking control is NOT measured: no bundle was rebuilt with the flag, so the rank is a prediction.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

README.md

@@ -80,6 +80,39 @@ than the clock, so two builds of the same folder are byte-identical — a
 wall-clock default would break rebuild-equals-incremental for every caller who
 did not pass them.
 
+### The segmentation flags
+
+Four rules are reachable from `okf build` and **all four are off by default**;
+a build with none of them is byte-identical to every bundle published here. Each
+line below carries the number it was measured at, and nothing beyond it — none
+of them is a recommendation, because which one should become the default has
+not been decided.
+
+| flag | what it does | measured |
+|---|---|---|
+| `--outline-run N` | also propose a boundary where the document's own bare-integer numbering sustains an ascending run of at least `N` | a tender PDF whose headings are bare integers: **no boundary** at `0`, **9 concepts** at `3`, against a reference of 9 |
+| `--table-grid` | a pandoc grid-table rule line no longer closes an open table block, so one grid table is one concept | a `.docx` experience list: **21 → 6** concepts |
+| `--unit-fold` | discard a contents-list run, fold a deeper heading into its parent, fold a table into the shorter heading that introduces it. Adds no boundary, so it can only reduce a plan | on a 12-document sample scored against an operator's unit worksheet: **5 of 12** match, against **2** for the default, no cell worse. Whole corpus: 679 → 485 proposed segments over 39 readable documents |
+| `--keep-table-heading` | keep a heading whose body is empty only because a table opens under it, and absorb that table into its span | the two spreadsheets in that corpus, and **0 of 32 `pdf` and 0 of 5 `docx`**: the concept count does not move (1 → 1), its first byte does — the concept gains the heading line it was missing |
+
+They compose, and the order above is the order they apply in. Measured on a
+five-document tender folder (2 `pdf`, 2 `docx`, 1 `xlsx`), concepts per
+document:
+
+| document | default | `--outline-run 3` | `+ --table-grid` | `+ --unit-fold` | `+ --keep-table-heading` |
+|---|---|---|---|---|---|
+| tender PDF, technical requirements | 1 (no boundary) | 9 | 9 | 9 | 9 |
+| tender PDF, technical layout | 1 (no boundary) | 1 | 1 | 1 | 1 |
+| price sheet `.xlsx` | 1 | 1 | 1 | 1 | 1 |
+| experience list `.docx` | 21 | 21 | 6 | 3 | 3 |
+| agreement `.docx` | 2 | 2 | 1 | 1 | 1 |
+| markdown files in the bundle | 31 | 49 | 33 | 30 | 30 |
+
+Every column merged 5 of 5 with 0 rejections. The reference for the first row
+is 9, so the default is a full arm behind what the proposer can do on that
+document — which is a statement about the default, not a licence to change it
+here.
+
 Measured 2026-09-08 on a 43-file corpus (33 `pdf`, 5 `docx`, 2 `xlsx`, and
 three files no reader accepts), one
 `okf build` invocation replacing the shell loop over `tools/` that produced the