session-memory: refresh published retro report artifacts

Latest retro publish (30-day window) regenerated last_retro.{json,md} — 30
ranked suggestions across 13 repos with catalog-sourced recommendations. This is
the read model published to the hub to unblock activity-core ACTIVITY-WP-0008.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

session_memory/retro/last_retro.json

@@ -1,5 +1,5 @@
 {
-  "generated_at": "2026-06-07T19:07:51Z",
+  "generated_at": "2026-06-07T19:30:56Z",
   "measure": {
     "error_rate": 0.957,
     "infra_overhead_share_median": 0.167,
@@ -316,7 +316,7 @@
   ],
   "window": {
     "days": 30,
-    "since": "2026-05-08T19:07:51Z",
-    "until": "2026-06-07T19:07:51Z"
+    "since": "2026-05-08T19:30:56Z",
+    "until": "2026-06-07T19:30:56Z"
   }
 }

session_memory/retro/last_retro.md

@@ -1,5 +1,5 @@
 # Weekly Coding Retro  (2026-05-08 → 2026-06-07)
-_23 real sessions · generated 2026-06-07T19:07:51Z_
+_23 real sessions · generated 2026-06-07T19:30:56Z_
 
 ## Top improvement suggestions (cross-flavor first, ≤3 per repo)
 - **net-kingdom** (high, score=54.0) [CROSS-FLAVOR]: cross-flavor problem: recurring error — Investigate recurring error on make: *** [makefile:<n>: fix-consistency] error <n>