ci: isole la base Postgres du job test par run

Deux jobs `test` qui se chevauchent (push de branche peu après un merge
sur `main`) se connectaient au *même* conteneur `--name postgres` sur le
réseau partagé du runner Forgejo : leurs `prisma migrate deploy` +
`seedReferenceData` (beforeAll racine Mocha) se télescopaient — P2002 sur
`key`, « No pending migrations » à tort, décalage des ids de
`tech_step`/`diet` cassant des assertions sans rapport. Vu 3× en une
session (PR #47, #53, #54), à chaque fois re-déclenché par un commit vide
sur un runner au repos.

`concurrency:` serait le correctif naturel mais ce Forgejo (9.0.3) est
antérieur à son support côté Actions (arrivé en Forgejo v14 / Gitea 1.26,
et workflow-level uniquement même là) : la clé est ignorée silencieusement.

À la place, le conteneur prend un nom unique par run
(`postgres-${GITHUB_RUN_ID}`), poussé dans `DATABASE_URL` via `$GITHUB_ENV`
pour les étapes suivantes — deux runs ne partagent plus jamais de base.
Nettoyage : étape de teardown `if: always()` + purge des conteneurs
abandonnés (bornée par l'âge) au démarrage, pour un job tué net avant son
teardown. `timeout-minutes: 40` borne aussi le cas « job zombie ~1h »
observé cette session (Mocha sans `--exit`).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -12,13 +12,18 @@ on:
   push:
 
 env:
-  # Hostname `postgres` = the container the `test` job starts itself (see
-  # that job's "Start Postgres" step) — a plain `docker run`, not a
-  # `services:` block, for the same reason the intent-service below can't be
-  # one: this repo's Forgejo `act` runner does not keep a `services:`
-  # container as the *same* instance across a job's steps, so `migrate
-  # deploy` would land the schema in one Postgres and `pnpm --filter api
-  # test`'s `beforeAll` would then hit an empty one ("table … does not
+  # Only the `test` job ever opens a database connection, and it *overwrites*
+  # this value at runtime (see its "Start Postgres" step) with a per-run
+  # hostname. This entry stays for one reason: `build`'s `pnpm install` runs
+  # `prisma generate` (apps/api `postinstall`), which wants DATABASE_URL to
+  # be present and syntactically valid — it never dials the host, so the
+  # literal `postgres` here need not resolve anywhere.
+  #
+  # Why the `test` job runs Postgres as a plain `docker run` and not a
+  # `services:` block: this repo's Forgejo `act` runner does not keep a
+  # `services:` container as the *same* instance across a job's steps, so
+  # `migrate deploy` would land the schema in one Postgres and `pnpm --filter
+  # api test`'s `beforeAll` would then hit an empty one ("table … does not
   # exist" right after "migrations successfully applied"). One long-lived
   # container in the job, shared by every step, removes that failure mode.
   DATABASE_URL: "postgresql://ci:ci@postgres:5432/batchcooking_ci?schema=public"
@@ -61,6 +66,13 @@ jobs:
 
   test:
     runs-on: ubuntu-latest
+    # Runaway ceiling, not a target: the job takes ~16-19 min normally (runs
+    # 117-121). Mocha runs with no `--exit` (`apps/api/.mocharc.json`), so a
+    # single leaked handle would otherwise hang this job until the runner's
+    # global timeout — a `test` job zombied for ~1h once before being
+    # cancelled by hand. 40 min leaves roughly 2x headroom for a slow /
+    # contended runner while still capping a hang at well under that hour.
+    timeout-minutes: 40
     steps:
       - name: Install curl and the docker CLI
         run: |
@@ -68,26 +80,70 @@ jobs:
 
       # Postgres as a plain background container instead of a `services:`
       # block — see this workflow's top-level `env.DATABASE_URL` comment for
-      # why. Reachable as `postgres` from this job (the runner mounts the
-      # docker socket and runs jobs on a shared user-defined network, so a
-      # `--name postgres` sibling resolves by name); the network is
-      # discovered from the job container itself rather than hardcoded.
+      # why. The runner mounts the docker socket and runs every job on one
+      # shared user-defined network, so a `--name` sibling resolves by name;
+      # the network is discovered from the job container itself rather than
+      # hardcoded.
+      #
+      # The container name carries the run id (`postgres-${GITHUB_RUN_ID}`)
+      # rather than a bare `postgres` *because* that network is shared by
+      # every job on this runner, across all branches. With a fixed name,
+      # two `test` jobs overlapping — a feature push landing within minutes
+      # of a `main` merge — both connected to the *same* container, and
+      # their `prisma migrate deploy` + `seedReferenceData` (root Mocha
+      # `beforeAll`) raced: `Unique constraint failed on the fields: (key)`
+      # in `seedReferenceData`, "No pending migrations to apply" when there
+      # should be some, `tech_step`/`diet` reference-row id shifts (+5)
+      # breaking unrelated assertions. Hit three times in one session (PRs
+      # #47, #53, #54), each needing an empty-commit re-trigger once the
+      # runner was idle. A GitHub-style `concurrency:` group on this job is
+      # the natural fix, but this Forgejo (9.0.3) predates Actions
+      # `concurrency` support entirely — it arrived in Forgejo v14 / Gitea
+      # 1.26 and the key is silently ignored on anything older. A per-run
+      # container name reaches the same end (no two runs share a database)
+      # with zero runner support required; the `if: always()` teardown step
+      # at the end of the job, plus the age-gated reap below, keep these
+      # per-run containers from piling up on the runner host.
       - name: Start Postgres in the background
         run: |
+          pg_host="postgres-${GITHUB_RUN_ID}"
+
+          # Best-effort reap of per-run Postgres containers left behind by a
+          # `test` job that was force-killed before its teardown step could
+          # run (SIGKILL skips `if: always()` steps). Age-gated well above
+          # this job's `timeout-minutes`, so a slower *concurrent* `test`
+          # job's container is never in range.
+          reap_before=$(( $(date +%s) - 7200 ))
+          for c in $(docker ps -aq --filter "name=postgres-"); do
+            started="$(docker inspect -f '{{.State.StartedAt}}' "$c" 2>/dev/null)" || continue
+            started_epoch="$(date -d "$started" +%s 2>/dev/null)" || continue
+            if [ "$started_epoch" -lt "$reap_before" ]; then
+              echo "reaping abandoned Postgres container $c (started $started)"
+              docker rm -f "$c" >/dev/null 2>&1 || true
+            fi
+          done
+
           net="$(docker inspect "$(hostname)" \
             --format '{{range $k, $_ := .NetworkSettings.Networks}}{{$k}} {{end}}' \
             | awk '{print $1}')"
           echo "job network: ${net:?could not determine the job container network}"
-          docker rm -f postgres >/dev/null 2>&1 || true
-          docker run -d --name postgres --network "$net" \
+          docker rm -f "$pg_host" >/dev/null 2>&1 || true
+          docker run -d --name "$pg_host" --network "$net" \
             -e POSTGRES_USER=ci -e POSTGRES_PASSWORD=ci -e POSTGRES_DB=batchcooking_ci \
             postgres:16-alpine
+
+          # Hand this run's hostname to every later step (prisma migrate
+          # deploy, pnpm --filter api test) — this line overrides the
+          # workflow-level env.DATABASE_URL, whose `postgres` host no longer
+          # resolves.
+          echo "DATABASE_URL=postgresql://ci:ci@${pg_host}:5432/batchcooking_ci?schema=public" >> "$GITHUB_ENV"
+
           for _ in $(seq 1 60); do
-            docker exec postgres pg_isready -U ci -d batchcooking_ci && exit 0
+            docker exec "$pg_host" pg_isready -U ci -d batchcooking_ci && exit 0
             sleep 2
           done
           echo "Postgres did not become ready in time" >&2
-          docker logs postgres || true
+          docker logs "$pg_host" || true
           exit 1
 
       - uses: https://github.com/actions/checkout@v4
@@ -134,6 +190,16 @@ jobs:
       - run: pnpm --filter api exec prisma migrate deploy
       - run: pnpm --filter api test
 
+      # Remove this run's Postgres even when a step above failed or the job
+      # hit its `timeout-minutes` — with a per-run name nothing else ever
+      # reuses or cleans it, and a bare `docker run` sibling outlives the job
+      # container. `|| true`: teardown must never itself fail the job. A job
+      # killed outright (SIGKILL, no `always()` step) is caught by the
+      # age-gated reap in "Start Postgres" on a later run.
+      - name: Stop this run's Postgres
+        if: always()
+        run: docker rm -f "postgres-${GITHUB_RUN_ID}" >/dev/null 2>&1 || true
+
   intent-service-test:
     runs-on: ubuntu-latest
     steps: