refactor(#2455): split hive-agent-mcp into its own bin crate

hive-ag3nt/src/serve_common.rs

@@ -5,7 +5,6 @@
 //! stay in the binary because they touch the request enum variants directly.
 
 use crate::events::Bus;
-use crate::mcp::REDELIVERY_HINT;
 use crate::turn::{TurnError, TurnOutcome};
 use crate::turn_stats::TurnStatRow;
 pub use hive_sh4re::wire_time::now_unix;
@@ -23,38 +22,20 @@ pub fn format_wake_prompt(
     unread: u64,
     redelivered: bool,
 ) -> String {
-    let banner = if redelivered { REDELIVERY_HINT } else { "" };
+    let banner = if redelivered {
+        hive_sh4re::REDELIVERY_HINT
+    } else {
+        ""
+    };
     let tag = if id > 0 {
         format!("[msg #{id}] ")
     } else {
         String::new()
     };
-    let pending = pending_hint(unread);
+    let pending = hive_sh4re::pending_hint(unread);
     format!("{banner}{tag}Incoming message from `{from}`:\n---\n{body}\n---{pending}")
 }
 
-/// Shared "(N more message(s) pending …)" advisory appended after both the
-/// wake prompt body and the `recv` tool result whenever the inbox still has
-/// queued messages once the current message/batch is popped. Returns an empty
-/// string when `remaining == 0`. The leading `\n\n` separates it from the
-/// preceding body/message block, and the suggested `max` is clamped to the
-/// server-side recv cap so the hint never asks for more than one round-trip
-/// can deliver. One builder so the wake prompt and the in-turn recv result
-/// stay identical.
-#[must_use]
-pub fn pending_hint(remaining: u64) -> String {
-    if remaining == 0 {
-        return String::new();
-    }
-    let batch = remaining.min(u64::from(hive_sh4re::RECV_BATCH_MAX));
-    format!(
-        "\n\n({remaining} more message(s) pending in your inbox — call `mcp__hyperhive__recv` \
-         with `max: {batch}` to drain the next batch before acting. If the \
-         backlog is stale/already handled, `ack_until(up_to: <highest [msg #N] seen>)` \
-         clears everything up to that id in one call instead.)"
-    )
-}
-
 /// Field-named args for [`build_row`]. Mirrors the turn-stats row
 /// columns; `outcome` and `bus` borrow for the duration of the call.
 pub struct TurnRowArgs<'a> {