refactor(#2352): quota enable/limit via daemon wire commands

hive-host-sock/src/lib.rs

@@ -164,6 +164,20 @@ pub enum HostRequest {
     /// (inline flag or stdin); the daemon just persists it. Read live by
     /// the agent's `gh` wrapper / git credential helper — no rebuild needed.
     SetAgentGithubToken { agent: String, token: String },
+    /// Turn on btrfs qgroup accounting on the agent-state filesystem, via
+    /// the privileged helper. Daemon-side equivalent of `hivectl quota
+    /// enable`. Returns advisory lines in [`HostResponse::messages`].
+    QuotaEnable,
+    /// Set (or, with `limit = None`, clear) an agent's btrfs disk quota via
+    /// the privileged helper. Daemon-side equivalent of `hivectl quota
+    /// limit`; the size string is parsed to bytes client-side. Returns a
+    /// bare success — the client prints the confirmation from the value it
+    /// sent.
+    QuotaLimit {
+        name: String,
+        #[serde(default)]
+        limit: Option<u64>,
+    },
 }
 
 /// Selects which container classes a hive-wide [`HostRequest::Stop`] /