refactor: single now_unix in hive_sh4re::wire_time

replaces 15 per-module copies (now_unix/now_secs) across hive-c0re and
hive-ag3nt; wire_time already owns the epoch-seconds convention

hive-c0re/src/scheduled_prompts.rs

@@ -18,6 +18,7 @@ use std::sync::Mutex;
 use anyhow::{Context, Result, bail};
 use rusqlite::{Connection, OptionalExtension, params};
 use serde::{Deserialize, Serialize};
+use hive_sh4re::wire_time::now_unix;
 
 /// Typed error returned by [`ScheduledPrompts::pause`] and
 /// [`ScheduledPrompts::resume`] when the target row does not exist or
@@ -674,13 +675,6 @@ fn load_targets(conn: &Connection, schedule_id: i64) -> Result<Vec<ScheduleTarge
     Ok(out)
 }
 
-fn now_unix() -> i64 {
-    std::time::SystemTime::now()
-        .duration_since(std::time::UNIX_EPOCH)
-        .ok()
-        .and_then(|d| i64::try_from(d.as_secs()).ok())
-        .unwrap_or(0)
-}
 
 #[cfg(test)]
 mod tests {