fix(ci): close 3 chronic Gitea-Actions workflow flakes (closes #88)

Three workflows have been failing on every push to this Gitea repo for
GitHub-shaped reasons that don't translate to act_runner. Surfaced
while landing #84; bundled per `feedback_gitea_actions_migration_audit_pattern`
("bundle per-repo, not per-finding") instead of three separate PRs.

1) handlers-postgres-integration: localhost → 127.0.0.1
   - lib/pq tries to dial localhost → ::1 first; the postgres service
     container only listens on IPv4 → ECONNREFUSED → all
     TestIntegration_* fail. Pin IPv4 to make the job deterministic.

2) pr-guards / disable-auto-merge-on-push: Gitea no-op
   - The previous reusable-workflow caller invoked `gh pr merge
     --disable-auto`, which calls GitHub's GraphQL API. Gitea returns
     HTTP 405 on /api/graphql → step always fails. Inline the step so
     it can detect Gitea (GITEA_ACTIONS=true OR repo url under
     moleculesai.app) and no-op with a notice. Auto-merge gating is
     moot on Gitea anyway: there's no `--auto` primitive being
     touched. Job stays ALWAYS-RUN so branch protection's required
     check still lands SUCCESS (avoids the SKIPPED-in-set trap from
     `feedback_branch_protection_check_name_parity`).

3) Harness Replays: cf-proxy nginx.conf via docker `configs:` (not bind)
   - act_runner runs the workflow inside a runner container; runc in
     the docker daemon below resolves bind-mount source paths on the
     OUTER host, not inside the runner. The path
     `/workspace/.../cf-proxy/nginx.conf` is invisible there → "not a
     directory" runc error. Switching to compose `configs:` packages
     the file as content rather than a host bind, sidestepping the
     DinD path-translation gap.

Local validation:
  - YAML parsed clean for all 3 files.
  - cf-proxy nginx.conf: standalone `docker compose run cf-proxy
    nginx -T` reproduced the configs: mount end-to-end and dumped the
    config correctly. The full harness compose still renders via
    `docker compose config`.

Real-CI verification will land on this branch's first push.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.github/workflows/handlers-postgres-integration.yml

@@ -97,7 +97,7 @@ jobs:
           # Wait for postgres to actually accept connections (the
           # GHA --health-cmd is best-effort but psql can still race).
           for i in {1..15}; do
-            if pg_isready -h localhost -p 5432 -U postgres -q; then break; fi
+            if pg_isready -h 127.0.0.1 -p 5432 -U postgres -q; then break; fi
             echo "waiting for postgres..."; sleep 2
           done
 
@@ -131,7 +131,7 @@ jobs:
           # not fine once a cross-table atomicity test came in.
           set +e
           for migration in $(ls migrations/*.sql 2>/dev/null | grep -v '\.down\.sql$' | sort); do
-            if psql -h localhost -U postgres -d molecule -v ON_ERROR_STOP=1 \
+            if psql -h 127.0.0.1 -U postgres -d molecule -v ON_ERROR_STOP=1 \
                   -f "$migration" >/dev/null 2>&1; then
               echo "✓ $(basename "$migration")"
             else
@@ -145,7 +145,7 @@ jobs:
           # fail if any didn't land — that would be a real regression we
           # want loud.
           for tbl in delegations workspaces activity_logs pending_uploads; do
-            if ! psql -h localhost -U postgres -d molecule -tA \
+            if ! psql -h 127.0.0.1 -U postgres -d molecule -tA \
                 -c "SELECT 1 FROM information_schema.tables WHERE table_name = '$tbl'" \
                 | grep -q 1; then
               echo "::error::$tbl table missing after migration replay — handler integration tests would be meaningless"
@@ -157,7 +157,14 @@ jobs:
       - if: needs.detect-changes.outputs.handlers == 'true'
         name: Run integration tests
         env:
-          INTEGRATION_DB_URL: postgres://postgres:test@localhost:5432/molecule?sslmode=disable
+          # 127.0.0.1, NOT localhost. On Gitea / act_runner the runner host
+          # has IPv6 enabled, so `localhost` resolves to `::1` first, and
+          # the Postgres service container only listens on IPv4 → lib/pq's
+          # first dial hits ECONNREFUSED. The migration step uses psql -h
+          # localhost which falls back to IPv4 cleanly, so the flake hides
+          # there and surfaces only at test time. Pinning IPv4 makes the
+          # whole job deterministic. (Issue #88, item 3.)
+          INTEGRATION_DB_URL: postgres://postgres:test@127.0.0.1:5432/molecule?sslmode=disable
         run: |
           go test -tags=integration -timeout 5m -v ./internal/handlers/ -run "^TestIntegration_"
 
@@ -167,5 +174,5 @@ jobs:
           PGPASSWORD: test
         run: |
           echo "::group::delegations table state"
-          psql -h localhost -U postgres -d molecule -c "SELECT * FROM delegations LIMIT 50;" || true
+          psql -h 127.0.0.1 -U postgres -d molecule -c "SELECT * FROM delegations LIMIT 50;" || true
           echo "::endgroup::"

.github/workflows/pr-guards.yml

@@ -1,14 +1,25 @@
 name: pr-guards
 
-# Thin caller that delegates to the molecule-ci reusable guard. Today
-# the guard is just "disable auto-merge when a new commit is pushed
-# after auto-merge was enabled" — added 2026-04-27 after PR #2174
-# auto-merged with only its first commit because the second commit
-# was pushed after the merge queue had locked the PR's SHA.
+# PR-time guards. Today the only guard is "disable auto-merge when a
+# new commit is pushed after auto-merge was enabled" — added 2026-04-27
+# after PR #2174 auto-merged with only its first commit because the
+# second commit was pushed after the merge queue had locked the PR's
+# SHA.
 #
-# When more PR-time guards land in molecule-ci, add them here as
-# additional jobs that share the same pull_request:synchronize
-# trigger.
+# Why this is inlined (not delegated to molecule-ci's reusable
+# workflow): the reusable workflow uses `gh pr merge --disable-auto`,
+# which calls GitHub's GraphQL API. Gitea has no GraphQL endpoint and
+# returns HTTP 405 on /api/graphql, so the job failed on every Gitea
+# PR push since the 2026-05-06 migration. Gitea also has no `--auto`
+# merge primitive that this job could be acting on, so the right
+# behaviour on Gitea is "no-op + green status" — not a 405.
+#
+# Inlining (vs. an `if:` on the `uses:` line) keeps the job ALWAYS
+# running, which matters for branch protection: required-check names
+# need a job that emits SUCCESS terminal state, not SKIPPED. See
+# `feedback_branch_protection_check_name_parity` and `feedback_pr_merge_safety_guards`.
+#
+# Issue #88 item 1.
 
 on:
   pull_request:
@@ -19,4 +30,34 @@ permissions:
 
 jobs:
   disable-auto-merge-on-push:
-    uses: molecule-ai/molecule-ci/.github/workflows/disable-auto-merge-on-push.yml@main
+    runs-on: ubuntu-latest
+    steps:
+      # Detect Gitea Actions. act_runner sets GITEA_ACTIONS=true in the
+      # step env on every job. Belt-and-suspenders: also check the repo
+      # url's host, which is independent of any runner-side env config
+      # (covers a future Gitea host where the env var is forgotten).
+      - name: Detect runner host
+        id: host
+        run: |
+          if [[ "${GITEA_ACTIONS:-}" == "true" ]] || [[ "${{ github.server_url }}" == *moleculesai.app* ]] || [[ "${{ github.event.repository.html_url }}" == *moleculesai.app* ]]; then
+            echo "is_gitea=true" >> "$GITHUB_OUTPUT"
+            echo "::notice::Gitea Actions detected — auto-merge gating is not applicable here (Gitea has no --auto merge primitive). Job will no-op."
+          else
+            echo "is_gitea=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Disable auto-merge (GitHub only)
+        if: steps.host.outputs.is_gitea != 'true'
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR: ${{ github.event.pull_request.number }}
+          REPO: ${{ github.repository }}
+          NEW_SHA: ${{ github.sha }}
+        run: |
+          set -eu
+          gh pr merge "$PR" --disable-auto -R "$REPO" || true
+          gh pr comment "$PR" -R "$REPO" --body "🔒 Auto-merge disabled — new commit (\`${NEW_SHA:0:7}\`) pushed after auto-merge was enabled. The merge queue locks SHAs at entry, so subsequent pushes can race. Verify the new commit and re-enable with \`gh pr merge --auto\`."
+
+      - name: Gitea no-op
+        if: steps.host.outputs.is_gitea == 'true'
+        run: echo "Gitea Actions — auto-merge gating not applicable; no-op (job intentionally green so branch protection's required-check name lands SUCCESS)."

tests/harness/compose.yml

@@ -167,6 +167,18 @@ services:
   # Production shape: same single CF tunnel front-doors every tenant
   # subdomain — the Host header carries the tenant identity, not the
   # routing destination. Local cf-proxy mirrors this exactly.
+  #
+  # nginx.conf delivery: docker compose `configs:` block (not a bind
+  # mount) so the file ships as content packaged by compose, not a
+  # host-path bind that has to be visible to the docker daemon's runc.
+  # Bind mounts break under Gitea's act_runner DinD because runc
+  # resolves the source path on the OUTER docker host (the runner's
+  # host filesystem), not inside the runner container — the path
+  # `/workspace/.../tests/harness/cf-proxy/nginx.conf` is only visible
+  # to the runner, not to the daemon below it. The `configs:` form
+  # uploads the file to the daemon as part of the service definition
+  # and is bind-mount-equivalent at the container level. See issue #88
+  # item 2.
   cf-proxy:
     image: nginx:1.27-alpine
     depends_on:
@@ -174,14 +186,23 @@ services:
         condition: service_healthy
       tenant-beta:
         condition: service_healthy
-    volumes:
-      - ./cf-proxy/nginx.conf:/etc/nginx/nginx.conf:ro
+    configs:
+      - source: cf-proxy-nginx-conf
+        target: /etc/nginx/nginx.conf
+        mode: 0444
     # Bind to 127.0.0.1 only — hardcoded ADMIN_TOKENs make 0.0.0.0
     # exposure unsafe even on a local network.
     ports:
       - "127.0.0.1:8080:8080"
     networks: [harness-net]
 
+configs:
+  # Defined once at compose level so any future service (e.g. a second
+  # nginx variant for an external-connect smoke test) can reuse the
+  # same source file.
+  cf-proxy-nginx-conf:
+    file: ./cf-proxy/nginx.conf
+
 networks:
   harness-net:
     name: molecule-harness-net