ci(portability): set the job limit from three green runs after #487 (#493)

Main runs 40935337099, 40938407252 and 40941240624 (dd247e3) took at most
7m24s, 7m31s and 7m32s (Windows), so the limit is ceil(1.5 x 7m32s) + 3 =
15 min, down from 27. The tooling test recomputes the limit from the
measurements written above jobs:.

.github/workflows/portability.yml

@@ -21,15 +21,16 @@ env:
   PYTHONFAULTHANDLER: "1"
 
 # Time limit rule as in test.yml: ceil(1.5 x the slowest of three recent green runs on main) + 3
-# minutes, never under 5. Measured 2026-10-26 in test.yml on runs 40257217681 (3be0ada),
-# 40240706568 (fb9134f), 40228167328 (f9835aa), before these legs moved here in #420:
-#   slowest py3.10 on windows-latest: 12m43s / 15m54s / 14m53s -> 27 min
-#     (macos 6m14s-8m30s, windows 11m42s-15m54s)
+# minutes, never under 5, timed as whole-job wall time. One matrix job, so the slowest leg of each
+# run counts (tests/vendor/ci-workflow.test.mjs recomputes it, #493).
+# Measured 2026-10-29 on main runs 40935337099 (dd247e3), 40938407252 (dd247e3), 40941240624 (dd247e3):
+#   slowest leg: 7m24s (py3.12 windows) / 7m31s (py3.13 windows) / 7m32s (py3.14 windows) -> 15 min
+#     (windows 4m56s-7m32s, macos 4m39s-6m14s)
 jobs:
   test:
     name: py${{ matrix.python-version }} on ${{ matrix.os }}
     runs-on: ${{ matrix.os }}
-    timeout-minutes: 27
+    timeout-minutes: 15
     strategy:
       fail-fast: false
       matrix:

.github/workflows/test.yml

@@ -28,8 +28,8 @@ env:
 #   py matrix, slowest py3.10 on windows-latest: 12m43s / 15m54s / 14m53s -> 27 min
 #     (ubuntu 5m27s-6m27s, macos 6m14s-8m30s, windows 11m42s-15m54s)
 #     3.10 and 3.11 left the matrix and 3.14 joined it in #356; re-measure after three green main runs.
-#     Windows and macOS moved to portability.yml (#420), which keeps this 27-minute limit; this
-#     Linux-only matrix keeps it too until it is re-measured.
+#     Windows and macOS moved to portability.yml (#420), which has its own measured limit (#493);
+#     this Linux-only matrix keeps 27 minutes until it is re-measured.
 #   real ComfyUI compatibility: 13m32s / 8m55s / 11m46s -> 24 min
 #   coverage gate (85%): 7m26s / 7m22s / 7m54s -> 15 min
 #   perf budget 30s / 29s / 27s, black and flake8 39s / 37s / 39s,