Fix remaining AGPL SPDX in Rust files and SHA-pin nested workflow actions

- AGPL-3.0-or-later → PMPL-1.0-or-later in .rs source files
- SHA-pin remaining checkout@v2/v3, upload-artifact@v3, cache@v3,
  setup-node@v3 in nested/submodule workflow files

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: hyperpolymath

verisimdb/verisimdb-data/dispatch/dispatch-2026-03-16.jsonl

@@ -1,5 +1,5 @@
 {
-  "checked_at": "2026-03-16T00:43:38.555883Z",
+  "checked_at": "2026-03-16T00:52:39.833241Z",
   "checks": {
     "circuit_breaker": {
       "failures": 0,
@@ -10,14 +10,14 @@
       "status": "pass"
     },
     "fleet_access": {
-      "last_modified": "{{2026, 3, 16}, {0, 43, 38}}",
-      "size_bytes": 1473618,
+      "last_modified": "{{2026, 3, 16}, {0, 52, 38}}",
+      "size_bytes": 1602032,
       "status": "pass"
     },
     "learning_scheduler": {
       "confidence_updates": 6,
-      "last_run": "~U[2026-03-16 00:43:43.508352Z]",
-      "outcomes_processed": 20401,
+      "last_run": "~U[2026-03-16 00:52:41.065045Z]",
+      "outcomes_processed": 21253,
       "status": "pass"
     },
     "recipe_health": {