feat: name the save folder and the pack on screen

The plan and the result now say how many files go to the save folder and
where, from a new saves event. With --from-pack they say the files come
from the pack, not a download. A stop asked for (Start+Select, SIGHUP)
ends on the plain outcome, without the log's last lines.

schemas/install-events.schema.json

@@ -21,6 +21,7 @@
         "declared",
         "found",
         "unreadable",
+        "saves",
         "download",
         "progress",
         "transfer",
@@ -64,6 +65,9 @@
     {
       "$ref": "#/$defs/unreadable"
     },
+    {
+      "$ref": "#/$defs/saves"
+    },
     {
       "$ref": "#/$defs/download"
     },
@@ -486,6 +490,31 @@
         }
       }
     },
+    "saves": {
+      "type": "object",
+      "additionalProperties": false,
+      "required": [
+        "event",
+        "platform",
+        "files",
+        "folder"
+      ],
+      "properties": {
+        "event": {
+          "const": "saves"
+        },
+        "platform": {
+          "type": "string"
+        },
+        "files": {
+          "type": "integer",
+          "minimum": 0
+        },
+        "folder": {
+          "type": "string"
+        }
+      }
+    },
     "download": {
       "type": "object",
       "additionalProperties": false,