Advance CUST-WP-0025: close T16/T17, add canon and fin-hub bootstrap

- Mark T16/T17 done with cutover evidence and decision coupling doc
- Add business-model-canvas and bootstrap-protocol canon (T20/T21)
- Record Core Hub readiness-summary evidence stubs
- Refresh fos-hub-bootstrap-sequence-status and core-hub-replacement-evidence

docs/evidence/core-hub-activity-core-sink-20260702.json

@@ -0,0 +1,14 @@
+[
+  {
+    "status": "posted",
+    "verified": true,
+    "eventId": "ae43db56-902d-411a-a495-25acd464fdd8",
+    "eventType": "ops-endpoint-verified",
+    "environment": "core-hub-staging",
+    "apiConsumerId": "6cfcbc56",
+    "apiConsumerKeyPrefix": "ch_ztkSv9PK",
+    "widgetId": "6768aaa2",
+    "containmentConfirmed": true,
+    "notes": "Non-secret evidence stub from CORE-WP-0004-T04 deployed activity-core Core Hub sink smoke."
+  }
+]