fix: address swarm review of consensus consolidation (PR #17)

From PR #17's own adversarial review (now running on the Phase-1 image — note
the much cleaner, less-fragmented findings). Graded in gadfly-reports.

- Never lose output (advisory invariant): run.sh writes a stub findings file
  when a model fails/skips under consolidation, so a failed model still shows
  (as failed) and an all-models-fail run still posts a comment.
- Errored models excluded from the agreement denominator (modelFindings.Errored
  + allErrored); shown folded as "reviewer failed", not counted as clean.
- Sliding cluster window: span [line,maxLine] widened by tolerance on both
  edges, so chains of nearby findings merge instead of splitting (fixes
  agreement under-counting). Clustering is now per-file (no global O(n²) scan).
- Lone-finding headline threshold raised high -> critical (matches the docs);
  only consensus or a lone critical earns the headline, the rest fold.
- findings_file_for appends a cksum so foo:bar vs foo/bar can't collide.
- mdCell escapes the location cell + neutralizes backticks (table-injection);
  "No material issues" no longer shown when folded findings exist.
- Removed dead cluster.detail; named findingRef type; single partition/agreed
  pass; writeFindingsOut MkdirAll; captureStdout defer-restore + close.

Tests added: sliding-window chain merge, errored-denominator exclusion, lone
HIGH folds. gofmt/vet/bash -n clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

entrypoint.sh

@@ -235,7 +235,16 @@ case "${GADFLY_CONSOLIDATE:-auto}" in
   0) CONSOLIDATE=0 ;;
   *) [ "${#MODEL_LIST[@]}" -ge 2 ] && CONSOLIDATE=1 ;;
 esac
-findings_file_for() { echo "${FINDINGS_DIR}/$(echo "$1" | tr -c '[:alnum:]._-' '_').json"; }
+# A model spec can contain '/' and ':' (e.g. claude-code/opus, qwen3:14b), so
+# sanitize to a flat filename — but append a checksum of the raw spec so two
+# specs that sanitize the same (foo:bar vs foo/bar -> foo_bar) don't collide onto
+# one file and silently drop a model from the consensus.
+findings_file_for() {
+  local safe sum
+  safe="$(echo "$1" | tr -c '[:alnum:]._-' '_')"
+  sum="$(printf '%s' "$1" | cksum | cut -d' ' -f1)"
+  echo "${FINDINGS_DIR}/${safe}-${sum}.json"
+}
 if [ "$CONSOLIDATE" = "1" ]; then
   rm -rf "$FINDINGS_DIR"; mkdir -p "$FINDINGS_DIR"
   log "consolidation ON: ${#MODEL_LIST[@]} models -> one consensus comment"