ci/manifest: publish on partial failure; fix built_at=; extend retry budget

.github/workflows/build.yml

@@ -16,6 +16,7 @@ jobs:
       head_sha:     ${{ steps.gate.outputs.head_sha }}
       short_sha:    ${{ steps.gate.outputs.short_sha }}
       build_id:     ${{ steps.gate.outputs.build_id }}
+      built_at:     ${{ steps.gate.outputs.built_at }}
     steps:
       - uses: actions/checkout@v4
       - id: gate
@@ -25,6 +26,7 @@ jobs:
           HEAD=$(git rev-parse HEAD)
           SHORT=$(git rev-parse --short HEAD)
           BUILD_ID="nightly-$(date -u +%Y%m%d)-${SHORT}"
+          BUILT_AT=$(date -u +%Y-%m-%dT%H:%M:%SZ)
           PREV=$(gh release view nightly --json body -q .body 2>/dev/null \
                   | sed -n 's/^sha=//p' | head -1 || true)
           if [ "${{ github.event_name }}" = "schedule" ] && [ "$PREV" = "$HEAD" ]; then
@@ -37,6 +39,7 @@ jobs:
           echo "head_sha=$HEAD"   >> "$GITHUB_OUTPUT"
           echo "short_sha=$SHORT" >> "$GITHUB_OUTPUT"
           echo "build_id=$BUILD_ID" >> "$GITHUB_OUTPUT"
+          echo "built_at=$BUILT_AT" >> "$GITHUB_OUTPUT"
 
   buildroot:
     name: Firmware
@@ -247,7 +250,11 @@ jobs:
           mkdir -p /tmp/ccache
           ln -s /tmp/ccache ${HOME}/.ccache
 
-          backoffs="30 60 120 300"
+          # Backoffs give 7 attempts total. The longer tail (600, 1200) covers
+          # the GitHub releases CDN / toolchain mirror flakes that took down
+          # hi3516av100_ultimate on 2026-05-20 (run 26196546684) — 502s
+          # storming for >10 min outlasted the previous 30/60/120/300 budget.
+          backoffs="30 60 120 300 600 1200"
           attempt=1
           for sleep_for in $backoffs ""; do
             make BOARD=${{matrix.platform}} && break
@@ -285,7 +292,7 @@ jobs:
           body: |
             sha=${{ needs.preflight.outputs.head_sha }}
             short=${{ needs.preflight.outputs.short_sha }}
-            built_at=${{ github.run_started_at }}
+            built_at=${{ needs.preflight.outputs.built_at }}
           files: |
             ${{env.NORFW}}
             ${{env.NANDFW}}
@@ -298,7 +305,7 @@ jobs:
           body: |
             sha=${{ needs.preflight.outputs.head_sha }}
             short=${{ needs.preflight.outputs.short_sha }}
-            built_at=${{ github.run_started_at }}
+            built_at=${{ needs.preflight.outputs.built_at }}
           files: |
             ${{env.NORFW}}
             ${{env.NANDFW}}

.github/workflows/manifest.yml

@@ -15,7 +15,14 @@ concurrency:
 jobs:
   generate:
     name: Generate manifest
-    if: github.event_name == 'workflow_dispatch' || github.event.workflow_run.conclusion == 'success'
+    # Publish on success AND on partial-failure: one flaky board (e.g. a
+    # transient toolchain 502) should not deny manifest updates for the 90+
+    # platforms that did upload artifacts. enrich_manifest.py reads whatever
+    # assets actually exist on the release, so a partial release just shows
+    # up with fewer platforms in its `platforms` map.
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      contains(fromJSON('["success", "failure"]'), github.event.workflow_run.conclusion)
     runs-on: ubuntu-latest
     steps:
       - name: Checkout master (for the script)