Add versioned ephemeral custody lifecycle

Assistant: codex
Assistant-Model: gpt-5.6-sol
Assistant-Session: 01a02669-87ee-7a31-b111-edc95a16e0fa

schemas/custody-cleanup-receipt.schema.json

@@ -0,0 +1,25 @@
+{
+  "$schema": "https://json-schema.org/draft/2020-12/schema",
+  "$id": "https://coulomb.social/schemas/railiance/custody-cleanup-receipt.v1.json",
+  "title": "Railiance custody cleanup receipt v1",
+  "type": "object",
+  "additionalProperties": false,
+  "required": [
+    "interface", "version", "workplan_id", "state", "lease_id", "engagement_id",
+    "projection_receipt_id", "cleaned_at", "removed_resources", "target_ready",
+    "secret_values_observed"
+  ],
+  "properties": {
+    "interface": {"const": "railiance.custody-cleanup-receipt"},
+    "version": {"const": 1},
+    "workplan_id": {"const": "RAILIANCE-WP-0025"},
+    "state": {"const": "cleaned"},
+    "lease_id": {"type": "string", "pattern": "^custody:[0-9a-f]{32}$"},
+    "engagement_id": {"type": "string"},
+    "projection_receipt_id": {"type": "string", "pattern": "^sha256:[0-9a-f]{64}$"},
+    "cleaned_at": {"type": "string", "format": "date-time"},
+    "removed_resources": {"type": "array", "items": {"type": "string"}},
+    "target_ready": {"const": true},
+    "secret_values_observed": {"const": false}
+  }
+}