feat(evals): stamp trial series identities and fit panels to the live registry

- scripts/eval-trial-series.ts stamps series_identity (eval-flake-rank's
  caseSeriesIdentities) on a report's trial-outcomes JSONL as its own step,
  keeping the history tool out of the paid runner's closure;
  TrialOutcomeRecord gains the optional series_identity field.
- Slice-count plans let a registered trial spill into an ordinary lane when
  its siblings hold every long lane, so panels never share a runner.
- Re-audited test-selection.ts (Stream B added the E2E_KINDS/BEHAVIOR_WHY
  map-diff; no new module loading) and repinned its hash.
- Detach and release floors now count trial shards (66 periodic trials in
  22 panels): periodic floor 33,821s, still under eval:bg:periodic's 67,380s.
- Coordination fixtures supply the executor's trial records.

scripts/eval-trial-series.ts

@@ -0,0 +1,35 @@
+#!/usr/bin/env bun
+/**
+ * Stamp `series_identity` on a report's trial-outcomes JSONL (the pass-rates
+ * history key: a hash of each case's own touchfiles, GLOBAL_TOUCHFILES
+ * excluded; scripts/eval-flake-rank.ts caseSeriesIdentities). A separate step
+ * after `test-paid-shards.ts --report`, so the paid runner's closure never
+ * imports the history tool.
+ *
+ * Usage: bun run scripts/eval-trial-series.ts <trial-outcomes.jsonl>
+ */
+import * as fs from 'node:fs';
+import * as path from 'node:path';
+import { caseSeriesIdentities } from './eval-flake-rank';
+import { formatTrialOutcomes, parseTrialOutcomes } from '../test/helpers/eval-store';
+
+const ROOT = path.resolve(import.meta.dir, '..');
+
+/** Rewrite the file with every record stamped; an invalid line fails the whole stamp. */
+export function stampTrialSeries(file: string, root = ROOT): number {
+  const { records, errors } = parseTrialOutcomes(fs.readFileSync(file, 'utf8'));
+  if (errors.length) throw new Error(`${file}: ${errors.join('; ')}`);
+  const identities = caseSeriesIdentities([...new Set(records.map(record => record.case))], root);
+  const stamped = records.map(record => ({ ...record, series_identity: identities[record.case] }));
+  fs.writeFileSync(file, formatTrialOutcomes(stamped));
+  return stamped.length;
+}
+
+if (import.meta.main) {
+  const file = process.argv[2];
+  if (!file) {
+    console.error('usage: bun run scripts/eval-trial-series.ts <trial-outcomes.jsonl>');
+    process.exit(2);
+  }
+  console.log(`[eval-trial-series] stamped ${stampTrialSeries(file)} record(s) in ${file}`);
+}