Add a consumption test for the compiled wiki

.gitignore

@@ -13,4 +13,6 @@ md/*
 # okf output folder
 okf/*
 !okf/
-!okf/.okflintrc.json
+!okf/.okflintrc.json
+# consumption-test transcripts (generated)
+tests/house-style/out/

docs/superpowers/specs/2026-07-31-okf-consumption-test-design.md

@@ -0,0 +1,138 @@
+# OKF consumption test — design
+
+**Date:** 2026-07-31
+**Status:** approved, for implementation
+
+## Problem
+
+`md2okf` is verified end to end as a *producer*: a 382 KB book compiles into a
+38-page OKF wiki that passes `okf-lint`. Nothing verifies the wiki is any
+*use*. Completeness and well-formedness are not usefulness, and OKF's own goals
+name consumption explicitly:
+
+> Inform how **consumption agents** should read and traverse it.
+> — `SPEC.md`, Goals §2
+
+So: can an agent holding only the compiled wiki apply the knowledge in it, and
+can we tell the difference between it having done so and it having guessed?
+
+## The prior-knowledge problem
+
+This is the crux. A capable model already knows roughly what Economist house
+style is. Hand it a badly written paragraph and a wiki, and a good rewrite
+proves nothing — it may never have opened a page.
+
+Two mitigations, both required:
+
+1. **Arbitrary rulings.** Cases are built on house rulings a model cannot
+   derive from general knowledge, several of which invert the common
+   convention. The strongest is `%`: most style guides prefer spelling out
+   "per cent", and this one requires the sign. A model working from priors gets
+   it backwards.
+2. **Verified citations.** Every change must cite the page it came from, and
+   grading checks the cited page *actually says so*. A plausible citation to a
+   page that does not support the claim fails.
+
+There is deliberately **no A/B control arm** (running each case again with the
+wiki absent). It would be the cleanest evidence of contribution, but it doubles
+the runs, and the counterintuitive rulings already give the test the ability to
+fail when the wiki is unread. Recorded as a known limitation, not an oversight.
+
+## Isolation
+
+A second Compose service, `pi-consume`, reusing the existing image:
+
+| Mount | Compile run | Consumption run |
+| --- | --- | --- |
+| `md/` | read-only | **absent** |
+| `okf/` | read-write | **read-only** |
+
+`md/` is unmounted so the agent cannot reach the source book — only the compiled
+wiki. `okf/` is read-only because consumption must not mutate the artefact under
+test; it also means the run needs no writable mount at all.
+
+The driver passes `--provider` and `--model` explicitly rather than editing
+`settings.json`, so the test states which model it exercised and leaves repo
+config untouched.
+
+## Output contract
+
+The agent writes nothing. Its final message is the result, captured from
+`pi -p` stdout, and must end with a fenced `json` block:
+
+```json
+{
+  "rewrite": "the corrected paragraph",
+  "changes": [
+    {
+      "before": "per cent",
+      "after": "%",
+      "ruling": "Use the sign % instead of per cent.",
+      "citation": "/part-2/7-sweating-the-small-stuff-punctuation-mechanics-and-conventions.md"
+    }
+  ]
+}
+```
+
+The grader reads the **last** fenced `json` block, so surrounding prose is
+harmless. A missing or unparseable block fails the case explicitly rather than
+scoring zero silently.
+
+## Grading
+
+Three mechanical assertions per case. No LLM judge — every check is a string or
+filesystem operation, so the result is deterministic and reproducible.
+
+1. **applied** — every `expect_present` string appears in `rewrite`, and every
+   `expect_absent` string does not.
+2. **cited** — at least one `changes[].citation` resolves to a file that exists
+   in the bundle.
+3. **grounded** — that cited file contains the case's `grounding` text.
+
+A case passes only when all three hold. Assertion 3 is what makes hallucinated
+citations fail: getting the edit right by luck and inventing a source still
+fails the case.
+
+## Cases
+
+All eight are verified present in the compiled wiki. `ch6` is
+`/part-2/6-confusables-and-cuttables-individual-rulings.md`.
+
+| # | Ruling | Page | Discriminates because |
+| --- | --- | --- | --- |
+| 1 | `%` not "per cent" | ch7 | inverts the usual convention |
+| 2 | do not verb "impact" | ch9 | house prohibition, not grammar |
+| 3 | "due to" modifies nouns only | ch6 | prefers *because of* / *owing to* |
+| 4 | "decimate" = a significant proportion | ch6 | not total destruction |
+| 5 | "fewer" for countables | ch6 | common error, explicit ruling |
+| 6 | no sentence-initial "Hopefully," | ch6 | explicitly *not* a grammar rule |
+| 7 | "alibi" ≠ excuse | ch6 | semantic ruling |
+| 8 | "compared with" for evaluation | ch6 | fine distinction against *compared to* |
+
+## Failure taxonomy
+
+Infrastructure failure must never read as "the wiki is bad". The driver exits:
+
+- `0` — all cases passed
+- `1` — at least one case failed on its assertions (a real result)
+- `2` — infrastructure trouble: missing key, gateway error, no wiki, no cases
+
+## Components
+
+| Path | Purpose |
+| --- | --- |
+| `pi/{container,sandbox}/…/skills/apply-house-style/SKILL.md` | the consumption task, one copy per runtime, aligned by hand |
+| `tests/house-style/cases.yaml` | fixtures: input, assertions, expected page, grounding |
+| `tests/house-style/grade.py` | the three assertions, table output, exit code |
+| `scripts/test-house-style.sh` | driver: one Pi run per case, then grade |
+| `pi/container/compose.yaml` | adds the `pi-consume` service |
+
+## Non-goals
+
+- **Navigability.** The container ships `ripgrep` and `fd`, so the agent will
+  likely grep rather than traverse `index.md` files. This test says nothing
+  about whether the index structure works.
+- **Prose quality.** Only the specific rulings are graded, not whether the
+  rewrite reads well.
+- **The sandbox runtime.** Implemented for parity, exercised on the container
+  runtime only, matching how every other result in this repo was obtained.

pi/container/agent/skills/apply-house-style/SKILL.md

@@ -0,0 +1,57 @@
+---
+name: apply-house-style
+description: Rewrite a paragraph to follow the house style recorded in the OKF wiki under okf/, citing the page each change came from. Use when a run asks you to apply house style to a passage.
+---
+
+# Apply house style from the wiki
+
+You are given one paragraph. Rewrite it so it follows the house style recorded
+in the OKF wiki under `okf/`, and say which page each change came from.
+
+The wiki is **read-only** in this run and there is no source document to fall
+back on — `okf/` is all you have, and it is the point. Answer from what the
+pages actually say, not from what you already believe about house style. The
+two often disagree, and here the wiki wins.
+
+## Procedure
+
+1. **Find the rulings.** Search `okf/` for the words and constructions used in
+   the paragraph. A ruling is usually a short section named after the word it
+   governs. Read the page before relying on it.
+2. **Apply only what you found.** Make a change when a page supports it. Do not
+   make stylistic improvements the wiki does not ask for — an unsupported change
+   cannot be cited, and uncited changes are the failure this task looks for.
+3. **Leave the rest alone.** Preserve the paragraph's meaning, facts and
+   figures. You are correcting style, not rewriting the argument.
+4. **Report** in the format below.
+
+## Output format
+
+End your reply with a fenced `json` block, and put nothing after it:
+
+````text
+```json
+{
+  "rewrite": "the full corrected paragraph",
+  "changes": [
+    {
+      "before": "the original wording",
+      "after": "the corrected wording",
+      "ruling": "a short quote of what the page says",
+      "citation": "/part-2/6-confusables-and-cuttables-individual-rulings.md"
+    }
+  ]
+}
+```
+````
+
+- `rewrite` — the whole paragraph, corrected. Not a diff, not a fragment.
+- `changes` — one entry per change. An empty list is a valid answer if the
+  wiki genuinely supports no change.
+- `ruling` — quote the page, briefly. Do not paraphrase it into something the
+  page does not say.
+- `citation` — a **bundle-absolute** path to a page that exists, rooted at the
+  wiki root: `/part-2/….md`, not `okf/part-2/….md` and not a relative path.
+
+Cite the page you actually read. A citation to a page that does not contain the
+ruling is worse than making no change at all: it presents a guess as sourced.

pi/container/compose.yaml

@@ -56,5 +56,53 @@ services:
       - ../../md:/workspace/md:ro
       - ../../okf:/workspace/okf:rw
 
+  # Consumption runtime: reads the compiled wiki, never writes it. Used by
+  # scripts/test-house-style.sh to check the wiki is usable, not merely
+  # well-formed. Two differences from `pi` above carry the whole point:
+  #
+  #   - md/ is NOT mounted, so the agent cannot reach the source documents and
+  #     must answer from okf/ alone. Mount it and the test proves nothing.
+  #   - okf/ is read-only, because the artefact under test must survive the test
+  #     unchanged. Nothing is written, so no writable mount is needed; the
+  #     agent's answer is its stdout.
+  #
+  # Neither key is required here — the driver selects a provider with
+  # --provider/--model, and only that provider's key has to be set.
+  pi-consume:
+    build:
+      context: ../..
+      dockerfile: pi/container/Dockerfile
+    image: pi-container
+
+    environment:
+      HOME: /home/node
+      OPENROUTER_API_KEY: ${OPENROUTER_API_KEY:-}
+      LITELLM_API_KEY: ${LITELLM_API_KEY:-}
+
+    network_mode: bridge
+    cap_drop:
+      - ALL
+    security_opt:
+      - no-new-privileges
+    read_only: true
+    user: "1000:1000"
+
+    pids_limit: 512
+    mem_limit: 4g
+    cpus: 2
+
+    tmpfs:
+      - /tmp
+      - /run
+      - /home/node
+
+    volumes:
+      - pi-agent-home:/home/node/.pi/agent
+      - ./agent/settings.json:/home/node/.pi/agent/settings.json:ro
+      - ./agent/models.json:/home/node/.pi/agent/models.json:ro
+      - ./agent/AGENTS.md:/home/node/.pi/agent/AGENTS.md:ro
+      - ./agent/skills:/home/node/.pi/agent/skills:ro
+      - ../../okf:/workspace/okf:ro
+
 volumes:
   pi-agent-home:

pi/sandbox/files/home/.pi/agent/skills/apply-house-style/SKILL.md

@@ -0,0 +1,57 @@
+---
+name: apply-house-style
+description: Rewrite a paragraph to follow the house style recorded in the OKF wiki under okf/, citing the page each change came from. Use when a run asks you to apply house style to a passage.
+---
+
+# Apply house style from the wiki
+
+You are given one paragraph. Rewrite it so it follows the house style recorded
+in the OKF wiki under `okf/`, and say which page each change came from.
+
+The wiki is **read-only** in this run and there is no source document to fall
+back on — `okf/` is all you have, and it is the point. Answer from what the
+pages actually say, not from what you already believe about house style. The
+two often disagree, and here the wiki wins.
+
+## Procedure
+
+1. **Find the rulings.** Search `okf/` for the words and constructions used in
+   the paragraph. A ruling is usually a short section named after the word it
+   governs. Read the page before relying on it.
+2. **Apply only what you found.** Make a change when a page supports it. Do not
+   make stylistic improvements the wiki does not ask for — an unsupported change
+   cannot be cited, and uncited changes are the failure this task looks for.
+3. **Leave the rest alone.** Preserve the paragraph's meaning, facts and
+   figures. You are correcting style, not rewriting the argument.
+4. **Report** in the format below.
+
+## Output format
+
+End your reply with a fenced `json` block, and put nothing after it:
+
+````text
+```json
+{
+  "rewrite": "the full corrected paragraph",
+  "changes": [
+    {
+      "before": "the original wording",
+      "after": "the corrected wording",
+      "ruling": "a short quote of what the page says",
+      "citation": "/part-2/6-confusables-and-cuttables-individual-rulings.md"
+    }
+  ]
+}
+```
+````
+
+- `rewrite` — the whole paragraph, corrected. Not a diff, not a fragment.
+- `changes` — one entry per change. An empty list is a valid answer if the
+  wiki genuinely supports no change.
+- `ruling` — quote the page, briefly. Do not paraphrase it into something the
+  page does not say.
+- `citation` — a **bundle-absolute** path to a page that exists, rooted at the
+  wiki root: `/part-2/….md`, not `okf/part-2/….md` and not a relative path.
+
+Cite the page you actually read. A citation to a page that does not contain the
+ruling is worse than making no change at all: it presents a guess as sourced.