ci: dump COPR per-chroot build logs to CI output

Previously the COPR publish steps only surfaced copr-cli's status
updates (pending/importing/running). When a build failed, diagnosing
required clicking through to the COPR web UI. Now we submit with
--nowait, watch the build, then use copr-cli download-build to fetch
each chroot's builder-live.log and cat them as collapsible ::group::
blocks in the CI output.

Logic is factored into .gitea/scripts/copr-build.sh so cortex and
neuron jobs share it. Both COPR jobs now check out the repo to access
the script.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.gitea/scripts/copr-build.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+# Submit an SRPM to COPR, watch the build, and dump per-chroot build logs
+# to stdout so they are captured in CI output.
+#
+# Usage: copr-build.sh <project> <srpm> [srpm...]
+# Example: copr-build.sh helexa/cortex ./cortex-0.1.2-1.fc43.src.rpm
+
+set -o pipefail
+
+PROJECT="$1"
+shift
+
+if [ -z "$PROJECT" ] || [ "$#" -eq 0 ]; then
+  echo "usage: $0 <project> <srpm> [srpm...]" >&2
+  exit 2
+fi
+
+# Submit without waiting; capture the build ID from stdout.
+SUBMIT_OUT=$(copr-cli build --nowait "$PROJECT" "$@")
+echo "$SUBMIT_OUT"
+BUILD_ID=$(echo "$SUBMIT_OUT" | grep -oP 'Created builds: \K[0-9]+' | head -n1)
+
+if [ -z "$BUILD_ID" ]; then
+  echo "error: could not parse build ID from copr-cli output" >&2
+  exit 1
+fi
+
+echo
+echo "Build $BUILD_ID submitted to $PROJECT"
+echo "Follow live: https://copr.fedorainfracloud.org/coprs/build/$BUILD_ID"
+echo
+
+# Watch the build; captures status transitions to stdout. Exit non-zero
+# on build failure, but defer propagating that until after we've fetched
+# logs so the CI output contains diagnostics either way.
+if copr-cli watch-build "$BUILD_ID"; then
+  STATUS=0
+else
+  STATUS=$?
+fi
+
+# Fetch per-chroot results (logs + rpms). Anonymous download — no auth needed.
+mkdir -p copr-logs
+copr-cli download-build --dest copr-logs "$BUILD_ID" || {
+  echo "warning: failed to download build artifacts" >&2
+}
+
+# Dump each chroot's builder-live.log as a collapsible group.
+for chroot_dir in copr-logs/*/; do
+  [ -d "$chroot_dir" ] || continue
+  chroot=$(basename "$chroot_dir")
+  log="${chroot_dir}builder-live.log"
+  if [ -f "$log" ]; then
+    echo
+    echo "::group::${chroot} builder-live.log"
+    cat "$log"
+    echo "::endgroup::"
+  fi
+done
+
+exit "$STATUS"