chore: gardener housekeeping 2026-03-23

- Update all AGENTS.md watermarks to HEAD (b276392)
- Clean up dust.jsonl: remove already-bundled items (601,627,739,741)
- Pending actions: promote #1099/#1100/#1101 to backlog, close stale
  prediction issues #1020/#1103/#1107, comment on partial resolution
  of #1022 (holdout resolved, user-test still empty)

gardener/pending-actions.json

@@ -0,0 +1,52 @@
+[
+  {
+    "action": "add_label",
+    "issue": 1099,
+    "label": "backlog"
+  },
+  {
+    "action": "add_label",
+    "issue": 1100,
+    "label": "backlog"
+  },
+  {
+    "action": "add_label",
+    "issue": 1101,
+    "label": "backlog"
+  },
+  {
+    "action": "comment",
+    "issue": 1103,
+    "body": "Closing as actioned. This prediction was logged and labeled prediction/actioned. The underlying issue (preflight.sh CI DB unreachable) has been noted by the team. Closing to keep the backlog clean."
+  },
+  {
+    "action": "close",
+    "issue": 1103,
+    "reason": "prediction actioned and stale"
+  },
+  {
+    "action": "comment",
+    "issue": 1107,
+    "body": "Closing as actioned. The double-crash on 2026-03-21 was transient — subsequent gardener runs including 2026-03-22 06:00 and 2026-03-23 07:03 completed successfully (PHASE:done). No recurring crash pattern observed. Closing."
+  },
+  {
+    "action": "close",
+    "issue": 1107,
+    "reason": "transient crash resolved — subsequent runs successful"
+  },
+  {
+    "action": "comment",
+    "issue": 1020,
+    "body": "Closing: evidence/evolution/ now contains data (best.push3). The fitness baseline absence predicted here has been resolved."
+  },
+  {
+    "action": "close",
+    "issue": 1020,
+    "reason": "evidence/evolution/ now populated with best.push3"
+  },
+  {
+    "action": "comment",
+    "issue": 1022,
+    "body": "Partial resolution: evidence/holdout/ now contains 2026-03-22-issue517-adversarial-lp.json. evidence/user-test/ remains empty — UX conversion signal still absent. Keeping open for user-test gap."
+  }
+]