Switch weekly trend workflow to artifacts instead of repo commits

Stores the failed-channel snapshot as a workflow artifact (90-day
retention) and downloads the previous run's artifact for comparison,
instead of committing a state file back to the repo.

.github/workflows/weekly_trend.yml

@@ -22,17 +22,29 @@ jobs:
           npm install -g iptv-checker || true
           sudo apt-get update && sudo apt-get install -y ffmpeg
 
+      - name: Download last week's snapshot (if any)
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          mkdir -p prev_snapshot
+          prev_run=$(gh run list --repo "${{ github.repository }}" --workflow weekly_trend.yml --status success --limit 1 --json databaseId -q '.[0].databaseId' || true)
+          if [ -n "$prev_run" ]; then
+            echo "Found previous successful run: $prev_run"
+            gh run download "$prev_run" --repo "${{ github.repository }}" -n checker-history -D prev_snapshot || echo "No artifact on that run (probably the very first one)."
+          else
+            echo "No previous successful run found — this is the first run."
+          fi
+
       - name: Run checker against the full playlist
         run: |
           mkdir -p output
           iptv-checker -o output -p 100 -t 120000 ./playlist.m3u8 || true
 
-      - name: Compare against last week's snapshot and update it
+      - name: Compare against last week's snapshot
         run: |
-          mkdir -p .github/checker-history
-          today=$(date -u +%Y-%m-%d)
-          prev_file=".github/checker-history/failed.txt"
-          curr_file=".github/checker-history/failed-current.txt"
+          mkdir -p snapshot
+          curr_file="snapshot/failed.txt"
+          prev_file="prev_snapshot/failed.txt"
 
           grep '^http' output/failed.m3u 2>/dev/null | sort -u > "$curr_file" || touch "$curr_file"
 
@@ -40,7 +52,7 @@ jobs:
           failed=$(grep -c '^#EXTINF' output/failed.m3u 2>/dev/null || echo 0)
 
           {
-            echo "## Weekly channel health trend — $today"
+            echo "## Weekly channel health trend — $(date -u +%Y-%m-%d)"
             echo ""
             echo "- Online: $online"
             echo "- Failed: $failed"
@@ -75,18 +87,9 @@ jobs:
             echo "_(no previous snapshot — this is the first run, nothing to compare against yet)_" >> "$GITHUB_STEP_SUMMARY"
           fi
 
-          mv "$curr_file" "$prev_file"
-
-      - name: Commit updated snapshot
-        run: |
-          git config user.name "PlaylistBot"
-          git config user.email "playlistbot@users.noreply.github.com"
-          git add .github/checker-history/failed.txt
-          git diff --staged --quiet && exit 0
-          git commit -m "Weekly checker snapshot ($(date -u +%Y-%m-%d))"
-          for i in 1 2 3 4 5; do
-            git fetch origin master
-            git rebase origin/master && git push && break
-            echo "Push attempt $i failed, retrying..."
-            sleep 5
-          done
+      - name: Upload this week's snapshot for next time
+        uses: actions/upload-artifact@v4
+        with:
+          name: checker-history
+          path: snapshot/failed.txt
+          retention-days: 90