The store's readiness is checked over TCP, not the socket

While the store initialises it runs a temporary server on the unix socket only,
then stops it and starts the real one. A socket check sees that temporary
server, the action exits happy, and the verify a moment later lands in the gap
between the two and fails — reported as "the action ran without error and its
own verify still fails", which is true and names nothing.

Intermittent, so it read as a slow machine. Both the action's own loop and its
verify now ask the same question, over the port the init phase deliberately
does not open: an action and its verify asking different questions is an action
that can succeed into a state its verify rejects.

examples/substrate-first-node.lock

@@ -58,12 +58,16 @@
       "ports": ["127.0.0.1:5432:5432"],
       "volumes": ["mesh-store-data:/var/lib/postgresql/data"]
     },
+    // Over TCP, not the socket. While the store initialises it runs a temporary server on the
+    // socket ONLY, then stops it and starts the real one — so a socket check passes, the action
+    // exits happy, and the verify a moment later lands in the gap and fails. The action and its
+    // verify must ask the same question, or the action can succeed into a state verify rejects.
     {
       "id": "store-ready",
       "type": "action",
       "in": "mesh-store",
-      "command": ["sh", "-c", "for i in $(seq 1 180); do pg_isready -U postgres >/dev/null 2>&1 && exit 0; sleep 1; done; echo 'the store did not answer within 180s; its own last words follow'; pg_isready -U postgres; tail -n 20 /var/lib/postgresql/data/log/*.log 2>/dev/null; exit 1"],
-      "verify": ["pg_isready", "-U", "postgres"]
+      "command": ["sh", "-c", "for i in $(seq 1 180); do pg_isready -h 127.0.0.1 -U postgres >/dev/null 2>&1 && exit 0; sleep 1; done; echo 'the store did not answer within 180s; its own last words follow'; pg_isready -h 127.0.0.1 -U postgres; tail -n 20 /var/lib/postgresql/data/log/*.log 2>/dev/null; exit 1"],
+"verify": ["pg_isready", "-h", "127.0.0.1", "-U", "postgres"]
     },
     {
       "id": "inventory-database",