docs: put the closing keyword where Gitea will actually read it

CLAUDE.md said the Closes list was unreliable and to close by hand. It
is unreliable for a specific reason, and the rule can say what works.

Gitea parses commit messages that reach main. It does not parse the PR
body, which closes something only if the merge happens to copy it into
the merge commit message. Both halves were measured here: #83's merge
commit carried "Closes #9, #13, #14, ..." and closed five of the ten,
because a comma list is only partially matched; #93's merge commit body
was a lone Reviewed-on: trailer, so #92 stayed open behind a perfectly
correct Closes line in the PR description.

So the keyword goes in the commit body as a footer, one issue per line.
That costs nothing elsewhere -- Conventional Commits allows a footer,
commit-check only regexes the subject, and semantic-release reads the
type from the subject, so no release decision changes. The existing
rule that the issue number stays out of the subject is untouched and
was never about the body.

The verification step stays, because a squash or a hand-edited merge
message still drops the footer.

This commit is the experiment: if #98 and #100 close when this branch
merges without anyone touching them, the mechanism is confirmed.

Closes #98
Closes #100

.gitea/workflows/unclaim.yml

@@ -1,86 +0,0 @@
-name: Unclaim
-
-# A `Closes #N` footer in a commit body closes the issue on merge — and
-# leaves `Status/In Progress` on it, because Gitea's auto-close touches
-# state and nothing else.  So #100 was closed and simultaneously marked
-# as being actively worked on, and `scripts/issue.sh close` (which does
-# drop the label) is exactly the thing the footer exists to avoid
-# calling.
-#
-# **This hooks the close, not the merge.**  Stripping the label in the
-# PR would work and would be a per-PR habit; habits are what the footer
-# removed.  `issues: [closed]` covers every path an issue can close by —
-# the footer on merge, `issue.sh close`, someone clicking Close in the
-# web UI — and asks nothing of anyone at any of them.
-#
-# **Reopening deliberately does not restore it.**  Reopening says the
-# work was not finished, not that somebody is at a keyboard doing it
-# now; the claim gets re-made by whoever picks it up.
-#
-# **This is not instant, and should not be described as it.**  The
-# runner has capacity 1 and is shared with an index build that can hold
-# it for three hours, so a label tweak can queue behind one. Stale for
-# an afternoon beats stale forever, which is what it was.
-#
-# The audit that answers "is this still firing" stays in CLAUDE.md and
-# is one command:
-#
-#   ./scripts/issue.sh list --state closed --label "Status/In Progress"
-#
-# A workflow that silently stops working is the failure mode this whole
-# area has already produced once.
-
-on:
-  issues:
-    types: [closed]
-
-jobs:
-  unclaim:
-    runs-on: ubuntu-latest
-    container:
-      image: ubuntu:24.04
-
-    steps:
-      - name: Drop the claim label
-        env:
-          # The automatic Actions token, as release.yml uses for the
-          # floor tag.  It needs no more than write access to this repo.
-          TOKEN: ${{ secrets.GITEA_TOKEN }}
-          API: ${{ github.server_url }}/api/v1/repos/${{ github.repository }}
-          ISSUE: ${{ github.event.issue.number }}
-        run: |
-          set -euo pipefail
-
-          apt-get update -qq
-          apt-get install -y -qq --no-install-recommends curl jq >/dev/null
-
-          label_id=$(
-            curl -sSf -H "Authorization: token $TOKEN" "$API/labels?limit=100" |
-              jq -r '.[] | select(.name == "Status/In Progress") | .id'
-          )
-
-          # The label not existing is a repo somebody reorganised, not a
-          # failure of this run — say so and stop, rather than failing a
-          # job on every close from then on.
-          if [ -z "$label_id" ]; then
-            echo "unclaim: no 'Status/In Progress' label in this repo; nothing to do"
-            exit 0
-          fi
-
-          # DELETE is idempotent here: an issue that never carried the
-          # label answers the same as one that did, which is what makes
-          # this safe to run on *every* close rather than only the ones
-          # that were claimed.
-          code=$(
-            curl -sS -o /dev/null -w '%{http_code}' -X DELETE \
-              -H "Authorization: token $TOKEN" \
-              "$API/issues/$ISSUE/labels/$label_id"
-          )
-
-          case "$code" in
-            204) echo "unclaim: #$ISSUE is closed and unclaimed" ;;
-            *)
-              echo "unclaim: DELETE returned $code for #$ISSUE" >&2
-              exit 1
-              ;;
-          esac

CLAUDE.md

@@ -85,18 +85,8 @@ release decision. The rule that the issue number stays out of the
 still drops the footer. `./scripts/issue.sh list --state open` after a
 merge, looking for what you just shipped; `./scripts/issue.sh close
 <n>` for whatever did not take, with a comment naming the commit.
-
-**Unclaiming is automatic, and it is hooked to the close rather than
-to the merge.** Gitea's auto-close changes state and nothing else, so a
-footer left `Status/In Progress` on a closed issue — #100 was closed
-and marked as being actively worked on at the same time.
-`.gitea/workflows/unclaim.yml` runs on `issues: [closed]`, which covers
-the footer, `issue.sh close` and a click in the web UI alike; stripping
-the label in the PR instead would have been a per-PR habit, and habits
-are what the footer removed. It is not instant — the runner has
-capacity 1 — and reopening deliberately does not restore the label.
-`./scripts/issue.sh list --state closed --label "Status/In Progress"`
-is how you find out it has stopped firing.
+`close` also drops `Status/In Progress`, because a claim outlives the
+work if nothing takes the label off.
 
 ## Planning
 
@@ -2186,11 +2176,10 @@ Pre-commit runs vet, lint, codegen check, and frontend typecheck in parallel. Pr
 
 ## CI
 
-Eight workflows in `.gitea/workflows/`. Five of them package and
+Seven workflows in `.gitea/workflows/`. Five of them package and
 publish (`arch-package`, `homebrew-formula`, `index-artifact`,
 `android-apk`, `desktop-assets`); `release.yml` decides *whether* four of
-those run at all; `unclaim.yml` is housekeeping on the tracker and
-touches no code; only `ci.yml` gates, and it is the one to look at when
+those run at all; only `ci.yml` gates, and it is the one to look at when
 deciding whether a push was healthy.
 
 **`release.yml` is the entry point for all of it.** On every push to