# Session 0015.0 — Transcript

> App: vscode-cowriting-plugin
> Start: 2026-06-10T22-37 (PST) · End: 2026-06-10T23-29 (PST)
> Type: planning-and-executing
> Driver: Claude (Opus 4.8) · Operator: Ben Stull
> Posture: autonomous (yolo, default)

## Launch prompt

```
Implement Feature #14 (F5 cross-rung format + round-trip) per the graduated spec vscode-cowriting-plugin-content/specs/coauthoring-cross-rung-format.md — plan just-in-time from its §7.2 slices, then execute; done = contract + schema published, unit + host E2E green (round-trip, merge, fail-safe, unknown-field preservation all exercised).
```

## Pre-state

- `main` clean and pushed; F4 (#12) shipped in session 0012; F5 spec graduated
  in session 0014 (`coauthoring-cross-rung-format.md`, all six forks resolved).
- Anchor: Feature #14 with an approved Solution Design — R2/R3 gate satisfied.
- No other sessions in flight (claim peek clean).

## Plan

Full plan: `docs/superpowers/plans/2026-06-10-f5-cross-rung-format.md`
(13 tasks; archived to content `plans/` at finalize). Slices → tasks:

- SLICE-1 (T1–T3): ajv devDep; `schemas/coauthoring-sidecar.schema.json` +
  `scripts/validate-sidecar.mjs` + schema unit suite; contract doc
  `specs/coauthoring-sidecar-contract.md` in the content repo (INV-14).
- SLICE-2 (T4–T8): Provenance `email`/`agent.onBehalfOf`; serializer
  unknown-field preservation (INV-15); `isNewerMajor` + store write-refusal
  backstop; `gitUserEmail` identity helper; `VersionGuard` read-only gating
  across all three controllers (INV-16, PUC-4).
- SLICE-3 (T9): pure `mergeArtifacts` + unit tests of every documented case
  (INV-17).
- SLICE-4 (T10–T11): `scripts/crossrung-reply.mjs` stand-in + byte-fidelity
  unit test; host E2E round-trip (PUC-2) + newer-major fail-safe (PUC-4).
- SLICE-5 (T12–T13): README pointers; full gate; PR + merge.

Execution mode: inline (superpowers:executing-plans).

## Session arc

1. **Init** — claimed 0015; baseline verified clean (`main` == `origin/main`
   after pulling our own claim commit); spec read end-to-end; codebase
   surveyed (model/store/controllers/E2E idioms).
2. **Plan** — just-in-time plan written from spec §7.2 (13 TDD tasks).
3. **SLICE-1** — ajv devDep (`0ddeaba`); JSON Schema 2020-12 + ajv validator
   script + `expectValidSidecar` test helper, schema suite green (`7c4d3ed`);
   **contract v1.0 published** to content repo
   (`specs/coauthoring-sidecar-contract.md`, `856553a`, pushed) — normative,
   status `living`, with serialization rules, field tables, INV-15/16
   compatibility rules, INV-17 merge rules, conforming-writer checklist,
   changelog.
4. **SLICE-2** — Provenance `email` + `agent.onBehalfOf` w/ optional-omission
   (`da172a3`); `withUnknowns()` unknown-field preservation at every
   serializer level, byte-stable (`a6b16f0`); `isNewerMajor` +
   `CoauthorStore.update` INV-16 throw backstop (`746071a`); `gitUserEmail`
   (vscode-free, exec git config, fail-open, cached) wired into both
   controllers' `currentAuthor()` (`ef4ec8d`); `VersionGuard` shared across
   the three controllers, gating every write gesture, one warning per doc,
   exposed on `CowritingApi` (`ef7d940`).
5. **SLICE-3** — `mergeArtifacts` pure reference implementation: union-by-id,
   thread shell/messages split, updatedAt-then-lexicographic resolution,
   conflicts surfaced, differing-major throw (`452f5d1`). One test-expectation
   fix mid-task: the divergent-message test asserted a human-intuitive winner;
   the deterministic tie-break legitimately picks the other side — corrected
   to assert determinism + symmetry.
6. **SLICE-4** — `crossrung-reply.mjs` stand-in (self-contained foreign
   writer; independent contract serialization; validates before/after;
   refuses newer majors) with byte-fidelity unit test vs the reference
   serializer — passed first try (`e0c127c`); host E2E: editor thread →
   stand-in reply (ELECTRON_RUN_AS_NODE) → external-change → message renders
   at re-resolved anchor (PUC-2); v2 sidecar → warning + bytes untouched
   through edit/save (PUC-4) (`5de59fd`).
7. **SLICE-5 + ship** — README cross-rung section (`abb9c88`); full gate
   green: typecheck · **98/98 vitest** · build · **18+3 host E2E**. Pushed,
   **PR #15** created via Gitea API and merged (`4651410`); **issue #14
   auto-closed**; branch deleted.
8. **Operator play feedback** — operator hit the dead "Reply…" input on a
   proposal thread (no submit command wired for `cowriting.proposals`).
   Answered (proposals are decide-only, INV-12; discussion = coauthoring
   thread) and fixed: `canReply=false` + test-facing `RenderedProposal.canReply`
   + E2E assertion; gate green; **PR #16** merged (`611a180`).
9. **Operator question (open)** — "show the operator's changes better from a
   diff perspective; easy toggle current ↔ diff view?" Answered with today's
   options (git Open Changes/gutter; F4 proposal diffs; attribution toggle)
   and named the gap: attribution is state-not-history, so a my-changes diff
   needs a baseline snapshot + virtual doc provider + toggle command. Offered
   to capture as a Feature issue; **no answer at finalize** — recorded in
   memory as the open idea.
10. **Finalize** (goal hook fired on achievement) — plan archived to content
    `plans/2026-06-10-f5-cross-rung-format.md` (`57f5827`); memory
    `f5-cross-rung-shipped.md` written + indexed; this transcript published.

## Cut state

- Plugin repo `main` @ `611a180` (PR #15 + #16 merged), pushed, no open PRs.
  Working tree clean except `sandbox/playground.md` (operator's play scratch
  — deliberately untouched).
- Content repo `main` @ `57f5827` (contract + archived plan), pushed.
  Untracked `issues/*.md` capture drafts predate this session (Author's).
- Issue #14 closed. **Epic #1 fully shipped** (F2 · F3 · F4 · F5).
- Pipeline (§9): VS Code extension — no deploy stage/PPE/browser surface; the
  app's required tier is host E2E, run green. Nothing deferred.

## Deferred decisions

- Inline execution chosen over subagent-driven (tasks share heavy
  `model.ts`/serializer context; single coherent feature).
- Thread-shell divergence rule: lexicographically-larger stable-stringify
  (makes "resolved" beat "open" deterministically) — documented in the
  contract; revisit at team rung if too naive.
- INV-15 implemented at the serializer level only (spec §6.2 wording);
  controller record-rebuild paths own their records.
- Stand-in writer deliberately re-implements contract serialization
  (executable documentation); byte-fidelity unit test is the drift tripwire.
- Merge tie-break is deterministic but not human-intuitive (lexicographic on
  stable-stringify); the divergent-message test was corrected to assert
  determinism + symmetry rather than a particular winner.
- Diff-view feature idea NOT filed as an issue (operator hadn't confirmed);
  recorded in memory instead.

## Operator plate

- Reload the extension dev host to pick up the PR #16 fix (rebuild first if
  not running `npm run watch`).
- Decide on the diff-view toggle idea: capture as a Feature issue, or drop.
- `sandbox/playground.md` left dirty for you.

## Next-session prompt

```
/goal Open a capture session for the diff-view toggle feature (operator's own changes as a toggleable diff vs a turn/accept baseline — sketch in memory f5-cross-rung-shipped), filing it as a typed Feature issue on benstull/vscode-cowriting-plugin
```

(Alternative frontier: the rfc-app#46 Gitea-substrate brainstorming — different
repo — which consumes the F5 contract as its input.)