fix: tool bugs found in review audit

repl:  env var was dead code (hardcoded 2s), empty frame gave misleading error
check-tangle: show full SBCL output on compile failure, not filtered
verify-repl: blacklist now configurable via VERIFY_REPL_EXCLUDE env var;
  regex tightened to ';; +REPL-VERIFIED:' from ';;.REPL.VERIFIED:' (ambiguous)
org-eval: 1-based indexing to match repl-block; errors on out-of-range; errors on <1

projects/verify-repl-tool/verify-repl

@@ -22,7 +22,9 @@ VIOLATIONS=0
 FILES_CHECKED=0
 
 # Blacklist: files exempt from REPL verification (core infrastructure, tests)
-BLACKLIST=(
+# Override with $VERIFY_REPL_EXCLUDE (space-separated filenames).
+# Example: VERIFY_REPL_EXCLUDE="setup.org package.lisp" verify-repl org/
+DEFAULT_BLACKLIST=(
     "core-defpackage.org"
     "core-manifest.org"
     "core-skills.org"
@@ -31,6 +33,12 @@ BLACKLIST=(
     "setup.org"
 )
 
+if [ -n "${VERIFY_REPL_EXCLUDE:-}" ]; then
+    IFS=' ' read -ra BLACKLIST <<< "$VERIFY_REPL_EXCLUDE"
+else
+    BLACKLIST=("${DEFAULT_BLACKLIST[@]}")
+fi
+
 is_blacklisted() {
     local fname
     fname=$(basename "$1")
@@ -75,7 +83,8 @@ check_file() {
             def_count=0
             has_repl_verify=0
             # Check for REPL-VERIFIED comment on previous line(s)
-            if echo "$prev_line" | grep -qE ';;.REPL.VERIFIED:'; then
+            # Matches ";; REPL-VERIFIED:" or ";;  REPL-VERIFIED:" etc.
+            if echo "$prev_line" | grep -qE ';; +REPL[-_]VERIFIED:'; then
                 has_repl_verify=1
             fi
             # Check for prose requirement: was there a headline before this block?