ci: fail the mutation floors step, and scale nightly property runs by a factor

The floors step piped scripts/mutation-floors.mjs into tee without
pipefail, so it took tee's exit status and a module under its floor could
never fail the run. It now runs under bash with pipefail, as do the other
steps that pipe into tee, and a guard reads every workflow and fails on a
tee pipe without it. The other piped steps were checked: each either
validates what the pipe produced or pipes a command that cannot fail.

The nightly runs set FC_NUM_RUNS, an absolute count that replaced every
property's own: the database backup round trip, which states twelve cases
for its cost, ran a hundred times against a timeout sized for twelve.
FC_RUNS_FACTOR now multiplies each property's count (five for the unit
suite, four for integration), propertyTimeout grows a test's timeout by
the same factor, and the backup round trip uses it.

.github/workflows/mutation.yml

@@ -35,8 +35,13 @@ jobs:
       - name: Run Stryker
         run: pnpm exec stryker run --concurrency 4
 
+      # Without pipefail the step takes the exit status of `tee`, which is
+      # always 0, so a module under its floor could never fail the run.
       - name: Check the per-module floors
-        run: node scripts/mutation-floors.mjs | tee -a "$GITHUB_STEP_SUMMARY"
+        shell: bash
+        run: |
+          set -o pipefail
+          node scripts/mutation-floors.mjs | tee -a "$GITHUB_STEP_SUMMARY"
 
       - name: Upload the report
         if: always()

.github/workflows/test-nightly.yml

@@ -58,9 +58,12 @@ jobs:
           echo "FC_SEED=$(( $(date +%s%N) % 2147483647 ))" >> "$GITHUB_ENV"
 
       - name: Unit tests, shuffled
+        shell: bash
         env:
-          FC_NUM_RUNS: "500"
+          # Five times each property's own case count (tests/property/fast-check.ts).
+          FC_RUNS_FACTOR: "5"
         run: |
+          set -o pipefail
           echo "Order seed ${TEST_SEED}, property seed ${FC_SEED}" | tee -a "$GITHUB_STEP_SUMMARY"
           pnpm exec vitest run --sequence.shuffle --sequence.seed="${TEST_SEED}" \
             --reporter=default --reporter=json --outputFile.json=unit-report.json
@@ -104,14 +107,18 @@ jobs:
           echo "FC_SEED=$(( ${{ github.run_id }} % 2147483647 ))" >> "$GITHUB_ENV"
 
       - name: Integration tests, shuffled
+        shell: bash
         env:
           HEALTHLOG_INTEGRATION_WORKERS: "3"
-          FC_NUM_RUNS: "100"
+          # Four times each property's own case count; a property's timeout
+          # grows by the same factor (`propertyTimeout`).
+          FC_RUNS_FACTOR: "4"
           # Quoted for the reason given in integration.yml.
           API_TOKEN_HMAC_KEY: "dddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddddd"
           ENCRYPTION_KEY: "0000000000000000000000000000000000000000000000000000000000000000"
           SESSION_SECRET: "integration-tests"
         run: |
+          set -o pipefail
           echo "Order seed ${TEST_SEED}, property seed ${FC_SEED}" | tee -a "$GITHUB_STEP_SUMMARY"
           pnpm exec vitest run --config vitest.integration.config.mts \
             --shard=${{ matrix.shard }}/4 \
@@ -150,7 +157,9 @@ jobs:
           path: reports
 
       - name: Regenerate
+        shell: bash
         run: |
+          set -o pipefail
           shopt -s nullglob
           integration=(reports/nightly-integration-report-*/*.json)
           unit=(reports/nightly-unit-report/*.json)