chore: move the CHANGELOG entry to changelog.d/capy-gsta149-free-runner.md (fragments policy since #3654)

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

CHANGELOG.md

@@ -1,18 +1,5 @@
 # Changelog
 
-## [Unreleased]
-
-**The free suite now runs on `ubicloud-standard-2` instead of `ubicloud-standard-8`, at the same 20 shards, for about a quarter of the runner cost.** Each shard runs its files one at a time, so it waits on disk and processes rather than CPU. In three paired rounds at one commit, the median per-shard time rose by 3 to 8 s, inside the round-to-round spread of −90 to +65 s, while runner-minutes stayed about equal (464 vs 475). Peak memory stayed under 2.5 GiB and free disk above 15 GiB. A 16-shard arm was slower beyond that spread, so the shard count stays at 20.
-
-### Changed
-- **`.github/workflows/free-tests.yml`**: one workflow-level `FREE_SUITE_RUNNER` (`ubicloud-standard-2`) and `FREE_SUITE_SHARDS` (`20`) set the free-suite size for pull_request, push and dispatch runs alike. `free-plan` resolves them into its `runner` output and the plan's shard count, and `free-suite` reads `runs-on` from that output. The duration-seed recorder stays on `ubicloud-standard-8`.
-- **Sizing experiments without a workflow edit**: `workflow_dispatch` takes `free_runner` (`ubicloud-standard-2`, `-4` or `-8` only) and `free_shards` (1–40). `free-plan` refuses any other value before planning, and a run that overrides either one says in its job summary that it is a sizing experiment, not a PR or train Free Tests result.
-- **Every free-suite shard prints `RESOURCES: peak_used_mib=… min_free_disk_mib=… samples=…`** from a memory and disk sample every 2 s, even when the suite fails. If a shard shows OOM, ENOSPC or an unexplained Chromium launch failure, move `FREE_SUITE_RUNNER` to `ubicloud-standard-4`.
-
-### Tests
-- `test/free-tests-workflow-wiring.test.ts`: runs the real `free-plan` step with a stubbed `bun`. It checks that the constant passes through when no override is given, that a valid override is honored, and that `ubuntu-24.04`, `ubicloud-standard-8 x`, `0`, `41` and `16; true` are refused before planning. It also checks that the sampler starts before the suite and that the report step runs `always()`.
-- `test/free-durations-record-workflow.test.ts`: the recorder and `FREE_SUITE_RUNNER` must both be Ubicloud standard runners. They no longer have to be the same size, because the recorder stays on standard-8.
-
 ## [1.91.319.0] - 2026-10-29
 
 **`gstack-pregate sealed` no longer prints a line that reads like a push confirmation.** On gstack-evals#29 the lane read `pushed aeb2413` in the `SEALED:` line as the push landing, while the remote stayed at 9036ab1 (#3565). `sealed` never pushes: it checks the commits a push would publish. `pushed <sha>` was its label for the commit whose `sealed` policy it read beside the base branch's.

changelog.d/capy-gsta149-free-runner.md

@@ -0,0 +1,10 @@
+**The free suite now runs on `ubicloud-standard-2` instead of `ubicloud-standard-8`, at the same 20 shards, for about a quarter of the runner cost.** Each shard runs its files one at a time, so it waits on disk and processes rather than CPU. In three paired rounds at one commit, the median per-shard time rose by 3 to 8 s, inside the round-to-round spread of −90 to +65 s, while runner-minutes stayed about equal (464 vs 475). Peak memory stayed under 2.5 GiB and free disk above 15 GiB. A 16-shard arm was slower beyond that spread, so the shard count stays at 20.
+
+### Changed
+- **`.github/workflows/free-tests.yml`**: one workflow-level `FREE_SUITE_RUNNER` (`ubicloud-standard-2`) and `FREE_SUITE_SHARDS` (`20`) set the free-suite size for pull_request, push and dispatch runs alike. `free-plan` resolves them into its `runner` output and the plan's shard count, and `free-suite` reads `runs-on` from that output. The duration-seed recorder stays on `ubicloud-standard-8`.
+- **Sizing experiments without a workflow edit**: `workflow_dispatch` takes `free_runner` (`ubicloud-standard-2`, `-4` or `-8` only) and `free_shards` (1–40). `free-plan` refuses any other value before planning, and a run that overrides either one says in its job summary that it is a sizing experiment, not a PR or train Free Tests result.
+- **Every free-suite shard prints `RESOURCES: peak_used_mib=… min_free_disk_mib=… samples=…`** from a memory and disk sample every 2 s, even when the suite fails. If a shard shows OOM, ENOSPC or an unexplained Chromium launch failure, move `FREE_SUITE_RUNNER` to `ubicloud-standard-4`.
+
+### Tests
+- `test/free-tests-workflow-wiring.test.ts`: runs the real `free-plan` step with a stubbed `bun`. It checks that the constant passes through when no override is given, that a valid override is honored, and that `ubuntu-24.04`, `ubicloud-standard-8 x`, `0`, `41` and `16; true` are refused before planning. It also checks that the sampler starts before the suite and that the report step runs `always()`.
+- `test/free-durations-record-workflow.test.ts`: the recorder and `FREE_SUITE_RUNNER` must both be Ubicloud standard runners. They no longer have to be the same size, because the recorder stays on standard-8.