* feat(#1680): ADR-1239 Phase C-1 — hook-bus + stateIO seams [AC4] Phase 3 slice 4 (AC4, final #1680 slice). The last two adapter seams behind the negotiated hookBus/stateIO axes: - src/hook-bus.cts: createHookBus({bus}, {hostEmit?}) -> host/engine/none. engine = in-process pub/sub (handler errors isolated); host = host-owned, fail-closed emit until a host emitter is bound; none = silent no-op (degrade to rule-text). PORTABLE_EVENT_FLOOR = SessionStart/PreToolUse/PostToolUse/ Stop/SessionEnd (the claude dialect all hook hosts share). - src/state-io.cts: createStateIO({io}, {backend?}) -> filesystem (today's behavior — straight fs) / sandboxed-storage / session-log-append (fail-closed seams until a host backend is bound). Proactive CI gates: ADR-457 ignores + INVENTORY-MANIFEST entries for both new .cjs; injection-scan 'act as' substring audit; unused-import check. All clean locally (11 tests + security 15/15 + inventory + eslint 0 problems). Phase 3 (#1680) seam layer now complete. Concrete host binding -> Phase 5 (#1682, D15/D18). * chore(changeset): add Changed fragment for hook-bus + stateIO seams (#1680)
Changeset Fragments
This directory holds per-PR CHANGELOG fragments. Every PR with user-facing changes drops one (or more) <random-name>.md files here describing its CHANGELOG entry. Fragments are consolidated into the top-level CHANGELOG.md at release time.
Why
Two PRs that both edit the ### Fixed block of CHANGELOG.md always conflict on merge — git can't pick a serialization order without human input. Two PRs that each add a fresh .changeset/<unique-name>.md never conflict because they don't share lines.
See #2975 for the full rationale.
Adding a fragment
node scripts/changeset/new.cjs \
--type Fixed \
--pr 1234 \
--body "fix the thing — explain the user-visible change in one sentence"
This writes .changeset/<adjective>-<noun>-<noun>.md with frontmatter and a body. Three random words → concurrent PRs don't collide.
Format
---
type: Fixed
pr: 1234
---
**`/gsd-foo` no longer drops trailing slashes** — explain the user-visible change.
Allowed type: values follow Keep a Changelog: Added, Changed, Deprecated, Removed, Fixed, Security.
Opting out
PRs that legitimately have no user-facing impact can add the no-changelog label. CI honors it. When unsure, add the fragment.
At release time
Promotion is automatic. The release workflow's finalize job runs:
node scripts/changeset/cli.cjs render --version vX.Y.Z --date YYYY-MM-DD --allow-empty
This reads every fragment, groups bullets by type:, replaces ## [Unreleased] with a new ## [vX.Y.Z] - YYYY-MM-DD block, opens a fresh ## [Unreleased] above, and deletes consumed fragments. The --allow-empty flag ensures a no-change release still gets a dated heading (with a _No notable changes._ placeholder). A subsequent verify step confirms the promotion landed correctly. Maintainers do not run this by hand.
Archived fragments
.changeset/archived/ holds fragments for already-shipped releases (≤ 1.3.1), retained for provenance. Their content was hand-curated into the dated ## [1.x.y] sections of CHANGELOG.md during the #690 backfill — they were never consumed by render. All changeset tooling enumerates .changeset/ non-recursively, so archived fragments are never picked up or rendered. Do not move them back to the top level.