fix(ci): reclaim disk before Android build

.gitea/workflows/pixel10.yml

@@ -143,6 +143,28 @@ jobs:
         # otherwise labels every one of those harmless lines as "ERROR".
         run: melos run build-go-runtime --no-select 2>&1
 
+      - name: Reclaim disk before Android build
+        shell: bash
+        run: |
+          set -euo pipefail
+
+          # These inputs and compiler caches are only needed to create the AAR
+          # installed by the previous step. Cargokit, Gradle and artifact upload
+          # need the reclaimed space later in the same job container.
+          rm -rf \
+            "$RUNNER_TEMP/sing-box" \
+            "$RUNNER_TEMP/IPtProxy" \
+            native/go_mobile_runtime/.work/android
+          go clean -cache -modcache
+
+          available_kib="$(df -Pk / | awk 'NR == 2 { print $4 }')"
+          minimum_kib=$((8 * 1024 * 1024))
+          df -h /
+          if (( available_kib < minimum_kib )); then
+            echo "At least 8 GiB of free runner disk is required before the Android build; only $((available_kib / 1024 / 1024)) GiB is available." >&2
+            exit 1
+          fi
+
       - name: Build and verify Pixel 10 APK
         env:
           GRADLE_OPTS: >-