F-catalog-B: npm_incoming and go_incoming read and drop the package seats' transfers; an idle one drops by its key

The package seats kept incoming, transfers and findings with no read or drop tool (tools review F4).
npm_incoming and go_incoming list a seat's open transfers, incoming's fill and the cap its binding carries,
and drop one by hand. The same fault as distribution's (running review F2, its second instance): the
transfers state's own lifetime dropped a transfer's key and left its chunks, and the drop otherwise waited
for the next publish. transfers keeps for good; each open transfer has a key in the new state idle with its
own time to live, whose end drops it. The holder counts against its binding's cap.

Claude-Session: https://claude.ai/code/session_01JG73KJNrH5EgFXMKKYSrig

modules/gitea/module.json

@@ -17,9 +17,14 @@
     {
       "name": "transfers",
       "storage": "key-value",
+      "template": "state"
+    },
+    {
+      "name": "idle",
+      "storage": "key-value",
       "template": "state",
       "options": {
-        "ttl-seconds": 86400
+        "key-ttl": true
       }
     },
     {