feat(ai-psychosis): add readRecentEndRecords for cross-session reads

plugins/ai-psychosis/hooks/scripts/lib.mjs

@@ -195,6 +195,37 @@ export function sessionsToday() {
   }
 }
 
+// Tail-first scan: return the N most recent end records (records with
+// duration_min defined) in chronological order. Cost is bounded by N, not
+// by total file size — a 50K-record sessions.jsonl is read once but only
+// the last few hundred lines are JSON-parsed before N is satisfied.
+export function readRecentEndRecords(n) {
+  if (!Number.isFinite(n) || n <= 0) return [];
+  if (!existsSync(SESSIONS_LOG)) return [];
+
+  let lines;
+  try {
+    lines = readFileSync(SESSIONS_LOG, 'utf8').split('\n');
+  } catch {
+    return [];
+  }
+
+  const collected = [];
+  for (let i = lines.length - 1; i >= 0 && collected.length < n; i--) {
+    const line = lines[i];
+    if (!line) continue;
+    try {
+      const rec = JSON.parse(line);
+      if (rec.duration_min !== undefined) {
+        collected.push(rec);
+      }
+    } catch { /* skip malformed */ }
+  }
+
+  // Reverse so caller receives oldest-first (chronological order).
+  return collected.reverse();
+}
+
 // --- State file management ---
 
 export function sessionStateFile(sid) {