measure: access-control feature table and separation screen (952 rows, 74 positive rows, 5 repositories); first ablation manifest registered

Three builds: the first two read 150 rows as empty (a producer bug, fcb43fd), the third is clean. The diff
producer was blind to removed lines (537b61e). Screen: deletion_count 0.89 is the reversed-fix construction;
on rows whose file lost lines entry_point_count 0.83 and caller_count 0.73 are the class signal; semantic covers
262 rows (TypeScript only). Repository folds assigned, leak audit recorded, manifest ac-ablation-1 registered
for decision (five arms, about 35 dollars).

Co-Authored-By: Claude Fable 5.1 <[email protected]>

benchmarks/measurements/2026-10-13-access-control-screen/summary.json

@@ -0,0 +1,24 @@
+{
+ "producer_rows_ok": {
+  "diff": 952,
+  "source": 933,
+  "semantic": 262,
+  "taxonomy": 952
+ },
+ "table_digest": "02774edc4c07dcc92b2fcf04ed342e7d0bc8afe761c808fef2d11b473bd99271",
+ "rows": 952,
+ "labelled": {
+  "positive": 74,
+  "negative": 878
+ },
+ "repositories": 5,
+ "changes": 105,
+ "positive_repositories": 5,
+ "source_failures": {
+  "FileNotFoundError": 16,
+  "ValueError": 3
+ },
+ "unread_rows": 0,
+ "positive_rows_on_changed_line": 12,
+ "positive_rows_with_deletions": 66
+}