catalog-schema: add CatalogLifecycle + reproducibility.seed_field

Resolves the stale-schema gap asset-engine-dev flagged (the published
schema rejected the lifecycle field 12/14 live services already use) and
adds reproducibility.seed_field so a seedable engine can declare which
response key carries the seed used. Authoritative regen path remains
dump_schema.py against asset_engine/catalog.py; reconcile there.

docs/asset-engine/services.schema.json

@@ -273,6 +273,40 @@
       "title": "CatalogLatency",
       "type": "object"
     },
+    "CatalogLifecycle": {
+      "additionalProperties": false,
+      "description": "Per-service orchestration metadata.\n\nPresence means \"asset_engine can start/stop this service from the UI\".\nAbsence (default) means \"managed externally \u2014 UI surfaces no controls.\"\nSee docs/contracts/orchestration.contract.md.\n\n  - stack:           directory name under /opt/docker/compose/ on the\n                     inference host (compose path derived).\n  - vram_gb:         VRAM the model needs at typical operating params.\n                     Used by the memory gate before docker compose up.\n  - gpu_device_id:   0 or 1 to pin to a specific card, None if the\n                     service uses both GPUs / picks dynamically. None\n                     means the gate must clear on each device.",
+      "properties": {
+        "stack": {
+          "minLength": 1,
+          "title": "Stack",
+          "type": "string"
+        },
+        "vram_gb": {
+          "exclusiveMinimum": 0,
+          "title": "Vram Gb",
+          "type": "number"
+        },
+        "gpu_device_id": {
+          "anyOf": [
+            {
+              "type": "integer"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null,
+          "title": "Gpu Device Id"
+        }
+      },
+      "required": [
+        "stack",
+        "vram_gb"
+      ],
+      "title": "CatalogLifecycle",
+      "type": "object"
+    },
     "CatalogModel": {
       "additionalProperties": false,
       "properties": {
@@ -333,6 +367,18 @@
           ],
           "default": null,
           "title": "Notes"
+        },
+        "seed_field": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null,
+          "title": "Seed Field"
         }
       },
       "required": [
@@ -571,6 +617,17 @@
           ],
           "default": null
         },
+        "lifecycle": {
+          "anyOf": [
+            {
+              "$ref": "#/$defs/CatalogLifecycle"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null
+        },
         "license": {
           "title": "License",
           "type": "string"