chore: cargo fmt --all — clean up a2a merge's fmt violations

The a2a merge (d0d8e7f) landed with a handful of pre-existing rustfmt
diffs that were failing `cargo fmt --all --check` in CI. Pure whitespace
reformatting from `cargo fmt --all`; no semantic changes. Files touched:
mcp_door.rs, quota.rs, routes/a2a.rs, routes/world.rs, runtime_provision.rs,
chat_repos.rs test, and tools/chat.rs.

crates/cm-api/src/routes/world.rs

@@ -182,10 +182,7 @@ fn normalize_run_event(
         }
         "a2a_invoked" => {
             // An external A2A caller started a turn on this agent (a new ingress).
-            out.push((
-                "a2a.invoked",
-                json!({ "agentId": agent_id }),
-            ));
+            out.push(("a2a.invoked", json!({ "agentId": agent_id })));
         }
         _ => {}
     }