docs-sync

# docs-sync -- per-PR documentation impact panel

The docs corpus drifts silently and constantly. This skill catches
drift at PR-open time, classifies its impact, and orchestrates a
persona panel to produce a patch-ready advisory comment.

The pattern is **A1 PANEL + B1 FAN-OUT/SYNTHESIZER + A8 ALIGNMENT
LOOP**. The classifier is the cost gate (~70% of PRs short-circuit
to no-change with ~1 LLM call). When the panel does fan out, every
agent reads a bounded context (~10 KB) -- never the full corpus.

This skill is ADVISORY. It does not gate merge, apply verdict
labels, or push to the contributor's fork. The orchestrator is the
sole writer to the PR: exactly one comment per run (idempotent
edit-in-place), plus optional label sweeps.

## Architecture invariants

- **Cost ceiling: 15 LLM calls per run.** Hard-wired. The orchestrator refuses to spawn beyond. Header prints `N/15` for observability.
- **Single-writer interlock.** Only the orchestrator writes. Panelist subagents return JSON; they MUST NOT call any `gh` write command, post comments, or touch PR state.
- **Idempotent comment.** Exactly one comment per run, with a stable header `## Docs sync advisory`. Re-runs edit-in-place using `gh pr comment --edit-last`.
- **No fork-write.** Companion docs PRs (only on structural verdict with `docs-sync-confirm` label) open from a bot branch in the BASE repo; never pushed to the contributor's fork.
- **Index-not-corpus reads.** Every classifier and architect agent reads `.apm/docs-index.yml`, NOT the corpus itself. The corpus is sampled only by the localizer (which reads the specific candidate pages) and by per-page panelists (which read one page each).
- **S7 deterministic tool bridge.** The python-architect panelist MUST run real `apm --help`, `grep`, and `python -c` commands to verify doc claims, never assert from prose.

## Roster

| Role | Agent | Always active? |
|---|---|---|
| Classifier | [doc-analyser](../../agents/doc-analyser.agent.md) inside [docs-impact-classifier](../docs-impact-classifier/SKILL.md) | Yes (every run) |
| Localizer | [docs-impact-localizer](../docs-impact-localizer/SKILL.md) | Only on `in_place` verdict |
| Architect | [docs-impact-architect](../docs-impact-architect/SKILL.md) | Only on `structural` verdict |
| Writer | [doc-writer](../../agents/doc-writer.agent.md) | Per candidate page (fan-out) |
| Verifier | [python-architect](../../agents/python-architect.agent.md) | Per candidate page (fan-out, S7) |
| Editorial | [editorial-owner](../../agents/editorial-owner.agent.md) | Once across all redrafts |
| Growth | [oss-growth-hacker](../../agents/oss-growth-hacker.agent.md) | Once across all redrafts |
| Synthesizer | [cdo](../../agents/cdo.agent.md) | Once, with ALIGNMENT LOOP up to 3 redrafts |

## Topology

```
   docs-sync SKILL (orchestrator thread)
                 |
   Step 1: classify (1 LLM call, may exit here)
                 |
                 v
            verdict?
            /    |    \
   no-change  in-place  structural
       |        |          |
     EXIT       |       architect (TOC delta)
                |          |
                +----<-----+
                |
   Step 2: localize (1 LLM call) -- per-page task brief
                |
   Step 3: FAN-OUT panel via task tool
                |
       +----+----+----+----+
       v    v    v    v    v
     writer  verify edit growth
     x N    x N   once  once
       (parallel; each <=10 KB context)
                |
   Step 4: schema-validate returns
                |
   Step 5: CDO synthesize (1 LLM call)
                |
            agree?
            / | \
        revise (N<=3 redrafts) | agree
                                  |
   Step 6: emit ONE comment via safe-outputs.add-comment
   Step 7: OPTIONAL companion docs PR (only if structural AND
           `docs-sync-confirm` label present)
```

## Execution checklist

### Step 1 -- Classify

Spawn ONE task: load the `docs-impact-classifier` skill, pass it the
PR number. It returns the classifier JSON.

Validate the JSON against `assets/classifier-return-schema.json`.
On schema failure, abort the run with a comment explaining the
internal error.

If verdict is `no_change`: skip to Step 6 with a brief advisory
("No docs impact detected. Reason: <one-line>. LLM calls: 1/15.")

### Step 2 -- Localize (in_place) or Architect (structural)

For `in_place`: spawn ONE task that loads the
`docs-impact-localizer` skill with the classifier output. Returns
per-page task briefs.

For `structural`: spawn ONE task that loads the
`docs-impact-architect` skill with the classifier output. Returns
TOC delta + new-page outlines + downstream in-place pages. THEN
spawn the localizer for those downstream pages.

### Step 3 -- Fan-out panel

**Cascade-size mitigation (PR 1244 class).** If `scope_pages[]` has
>8 entries, the per-page fan-out at one writer call per page would
approach the 15-call ceiling with no headroom for verifier redrafts.
BEFORE spawning, group `scope_pages[]` into SECTIONS:

- Pages under the same TOC section (e.g. all `consumer/**`) with the
  SAME conceptual fix (e.g. "rename apm update -> apm self-update in
  every mention") become ONE writer task with a `pages_in_section[]`
  array in its brief.
- A 9-page rename cascade collapses to 2-3 section writer tasks.

The python-architect verifier still runs per `verify_claims[]` (not
per page), because S7 evidence is keyed on claims, not pages.

For each page-or-section in the per-page task brief, spawn TWO parallel tasks:

1. **doc-writer** task -- drafts the patch for that page's (or section's) specific edits. Output: JSON with `before:`, `after:` for each location.
2. **python-architect** task -- for each `verify_claims[]` in the page brief, run the actual command (S7 tool bridge: `apm <verb> --help`, `grep -n <symbol> src/`). Output: JSON with `claim: verified | refuted | inconclusive` per claim.

In parallel with the per-page fan-out, spawn ONCE each:

3. **editorial-owner** task -- recei