feat: convert unreleased changelog to fragments

.github/pull_request_template.md

@@ -12,8 +12,8 @@ to the issue for triage to amend, not silently unshipped. -->
 
 ## Changelog
 
-- [ ] One line under `## Unreleased` — inserted **above** the heading below
-      it, never over it — or no behavior change, stated here.
+- [ ] One `changelog.d/<issue>.md` fragment containing the exact publishable
+      prose — or no behavior change, stated here.
 
 ## Round log
 

CHANGELOG.md

@@ -4,30 +4,6 @@ History before 0.1.0 lives in git — rig grew its version surface (`VERSION`,
 `rig --version`, the side-by-side `versions/<v>` install layout; #35/#36)
 on the way to cutting its first release, and this file starts there.
 
-## Unreleased
-
-### Added
-
-- `drill/drill.sh` — the drill has an instrument: pinned-ref assertion, a mechanical idempotence diff, and a `drills/<version>.md` record emitter (#105)
-- GitHub entry templates route humans to Discussions and prefill triage work orders and pull requests (#123)
-- `rig platform` prints a stable machine `ID`, derived from `/etc/machine-id`, never the raw value (#95)
-- Platform, drill, docs and labels changes receive dedicated scope labels (#119)
-- CI drills the install lifecycle against a real tree — install from the checkout, converge to an empty diff, uninstall to proven absence (#106)
-- `rig bootstrap --undo` removes only a tailnet join rig can prove it made (#63)
-- `kimi-box` joins the box tenant roles — the Kimi CLI agent guest (#109)
-- The `changelog-armed` guard returns, version-keyed (#112, ceremony#13)
-- The `.ceremony/` doctrine mirror, verified by `docs-sync` on every PR (#112, ceremony#19)
-
-### Changed
-
-- `bootstrap --host yes` installs a pinned box release instead of `main` (#103)
-- Release and labels machinery is consumed from heavy-duty/ceremony@0.1.0 by reference — the workflows shrink to caller stubs, the guard scripts and their tests move upstream (#112, ceremony#13)
-
-### Fixed
-
-- The drill's docs no longer claim both installers default to `main` — box installs the `BOX_RELEASE` pin, rig the latest release, and its `--box-ref` example is now a tag (#133)
-- `kimi-bot-andresmgsl` is on the review panel — the roster predated it joining the bench (#120)
-
 ## 0.3.0 — 2026-07-21
 
 ### Fixed

CONTRIBUTING.md

@@ -25,14 +25,16 @@ genuinely rig's.
    round-trip (`test/db-integration.sh`) executes in CI where Docker is
    present. The release guards (`changelog-armed`, `changelog-monotonic`,
    `drill-recorded`, `docs-sync`) run as ceremony's pinned actions.
-4. **Feature PRs land their changelog entry as part of the PR**: add it
-   under `CHANGELOG.md`'s `## Unreleased` heading — that section becomes
-   the release notes verbatim when a release is cut.
+4. **Feature PRs land their changelog entry as part of the PR**: write
+   `changelog.d/<issue>.md` — the release PR assembles those fragments into
+   the release notes verbatim.
 
 ## Changelog entries
 
-Every PR that changes behaviour adds one line to `## Unreleased`. One line is
-the whole rule — if it wraps more than twice in your editor, cut it down.
+Every PR that changes behaviour writes one `changelog.d/<issue>.md` fragment.
+The fragment keeps the relevant `### Added` / `### Changed` / `### Fixed`
+heading above its entry. One line is the whole rule — if it wraps more than
+twice in your editor, cut it down.
 
 - **Say what changed, and stop.** Why it was wrong, how it was found, what it
   cost, what it implies — that belongs in the PR body and the commit message,

changelog.d/103.md

@@ -0,0 +1,3 @@
+### Changed
+
+- `bootstrap --host yes` installs a pinned box release instead of `main` (#103)

changelog.d/105.md

@@ -0,0 +1,3 @@
+### Added
+
+- `drill/drill.sh` — the drill has an instrument: pinned-ref assertion, a mechanical idempotence diff, and a `drills/<version>.md` record emitter (#105)

changelog.d/106.md

@@ -0,0 +1,3 @@
+### Added
+
+- CI drills the install lifecycle against a real tree — install from the checkout, converge to an empty diff, uninstall to proven absence (#106)

changelog.d/109.md

@@ -0,0 +1,3 @@
+### Added
+
+- `kimi-box` joins the box tenant roles — the Kimi CLI agent guest (#109)

changelog.d/112.md

@@ -0,0 +1,8 @@
+### Added
+
+- The `changelog-armed` guard returns, version-keyed (#112, ceremony#13)
+- The `.ceremony/` doctrine mirror, verified by `docs-sync` on every PR (#112, ceremony#19)
+
+### Changed
+
+- Release and labels machinery is consumed from heavy-duty/ceremony@0.1.0 by reference — the workflows shrink to caller stubs, the guard scripts and their tests move upstream (#112, ceremony#13)

changelog.d/119.md

@@ -0,0 +1,3 @@
+### Added
+
+- Platform, drill, docs and labels changes receive dedicated scope labels (#119)

changelog.d/120.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- `kimi-bot-andresmgsl` is on the review panel — the roster predated it joining the bench (#120)

changelog.d/123.md

@@ -0,0 +1,3 @@
+### Added
+
+- GitHub entry templates route humans to Discussions and prefill triage work orders and pull requests (#123)

changelog.d/133.md

@@ -0,0 +1,3 @@
+### Fixed
+
+- The drill's docs no longer claim both installers default to `main` — box installs the `BOX_RELEASE` pin, rig the latest release, and its `--box-ref` example is now a tag (#133)

changelog.d/136.md

@@ -0,0 +1,3 @@
+### Changed
+
+- Changelog entries land in per-issue fragments assembled by the release PR (#136)

changelog.d/63.md

@@ -0,0 +1,3 @@
+### Added
+
+- `rig bootstrap --undo` removes only a tailnet join rig can prove it made (#63)

changelog.d/95.md

@@ -0,0 +1,3 @@
+### Added
+
+- `rig platform` prints a stable machine `ID`, derived from `/etc/machine-id`, never the raw value (#95)

changelog.d/README.md

@@ -0,0 +1,10 @@
+# changelog.d/ — the next release's section, one fragment per issue
+
+Machine-assembled by `bin/changelog-assemble` (#112): every PR that changes
+behavior writes one file here — `<issue>.md`, the exact prose that will be
+published, nothing else — and the release PR folds them all into the next
+`## X.Y.Z — DATE` section of `CHANGELOG.md`, consuming them. Distinct
+filenames never conflict, which is this directory's whole reason to exist.
+This README is the marker that keeps the directory tracked when it holds no
+fragments (#112 D1) — `changelog-armed` refuses a tree without it; do not
+delete it.