feat(real-world-vfc-slice): add labeled OpenSSL/Firefox/Chromium/curl pair corpus

Harvest 176 isolated vuln-vs-fix functions (109 CVEs, 352 training rows)
into benchmarks/pairs/vfc with provenance and a JSONL training manifest.
Score the slice as an honesty dashboard (ousast pairs --slice vfc);
keep the pair gate on the local fixtures only.

benchmarks/pairs/vfc/openssl-cve-2022-2068-hash_dir/fixed.in

@@ -0,0 +1,47 @@
+/* Provenance: openssl/openssl hash_dir (fixed).
+ * repo: openssl/openssl
+ * commit: 2c9c35870601b4a44d86ddbf512b38df38285cfa
+ * parent: abebcec7b1a30fbb1fd5c5cbbe8817690c139163
+ * commit_url: https://github.com/openssl/openssl/commit/2c9c35870601b4a44d86ddbf512b38df38285cfa
+ * cve: CVE-2022-2068
+ * license: Apache-2.0
+ * function: hash_dir
+ * relpath: tools/c_rehash.in
+ */
+
+sub hash_dir {
+    my $dir = shift;
+    my %hashlist;
+
+    print "Doing $dir\n";
+
+    if (!chdir $dir) {
+        print STDERR "WARNING: Cannot chdir to '$dir', $!\n";
+        return;
+    }
+
+    opendir(DIR, ".") || print STDERR "WARNING: Cannot opendir '.', $!\n";
+    my @flist = sort readdir(DIR);
+    closedir DIR;
+    if ( $removelinks ) {
+        # Delete any existing symbolic links
+        foreach (grep {/^[\da-f]+\.r{0,1}\d+$/} @flist) {
+            if (-l $_) {
+                print "unlink $_\n" if $verbose;
+                unlink $_ || warn "Can't unlink $_, $!\n";
+            }
+        }
+    }
+    FILE: foreach $fname (grep {/\.(pem)|(crt)|(cer)|(crl)$/} @flist) {
+        # Check to see if certificates and/or CRLs present.
+        my ($cert, $crl) = check_file($fname);
+        if (!$cert && !$crl) {
+            print STDERR "WARNING: $fname does not contain a certificate or CRL: skipping\n";
+            next;
+        }
+        link_hash_cert($fname) if ($cert);
+        link_hash_crl($fname) if ($crl);
+    }
+
+    chdir $pwd;
+}