chanserv: channel SUSPEND / UNSUSPEND (oper-gated)

Freezes a channel gated on Priv::Suspend: a typed Suspension on ChannelInfo
(event-logged, snapshotted, lazy expiry — same shape as the account one, no
Anope Extensible/Checker or expiry timer). While suspended, ChanServ refuses
all management (guards in require_op/require_founder and the founder-inline
SET/DROP/MLOCK), the engine skips Join enforcement (no auto-op/akick/entrymsg),
and suspending kicks everyone out; INFO shows it. parse_duration moved into the
SDK so both SUSPEND commands share it. Data + full-flow tests.

chanserv/src/suspend.rs

@@ -0,0 +1,53 @@
+use fedserv_api::{parse_duration, NetView, Priv, Sender, ServiceCtx, Store};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+// SUSPEND <#channel> [+expiry] [reason] / UNSUSPEND <#channel>: freeze or unfreeze
+// a channel. Its data is kept but it can't be managed while suspended. Oper-only
+// (Priv::Suspend). `suspending` selects SUSPEND vs UNSUSPEND.
+pub fn handle(me: &str, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &dyn NetView, db: &mut dyn Store, suspending: bool) {
+    if !from.privs.has(Priv::Suspend) {
+        ctx.notice(me, from.uid, "Access denied — that command is for services operators.");
+        return;
+    }
+    let Some(&chan) = args.get(1) else {
+        let syntax = if suspending { "Syntax: SUSPEND <#channel> [+expiry] [reason]" } else { "Syntax: UNSUSPEND <#channel>" };
+        ctx.notice(me, from.uid, syntax);
+        return;
+    };
+    if db.channel(chan).is_none() {
+        ctx.notice(me, from.uid, format!("\x02{chan}\x02 isn't registered."));
+        return;
+    }
+
+    if !suspending {
+        match db.unsuspend_channel(chan) {
+            Ok(true) => ctx.notice(me, from.uid, format!("\x02{chan}\x02 is no longer suspended.")),
+            Ok(false) => ctx.notice(me, from.uid, format!("\x02{chan}\x02 isn't suspended.")),
+            Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+        }
+        return;
+    }
+
+    let mut rest = &args[2..];
+    let expires = rest.first().and_then(|t| t.strip_prefix('+')).and_then(parse_duration).map(|secs| now_unix() + secs);
+    if expires.is_some() {
+        rest = &rest[1..];
+    }
+    let reason = if rest.is_empty() { "This channel has been suspended.".to_string() } else { rest.join(" ") };
+    let by = from.account.unwrap_or(from.nick);
+    match db.suspend_channel(chan, by, &reason, expires) {
+        Ok(()) => {
+            // Clear the channel: kick everyone currently in it.
+            for uid in net.channel_members(chan) {
+                ctx.kick(me, chan, &uid, &reason);
+            }
+            let expiry = if expires.is_some() { " (with expiry)" } else { "" };
+            ctx.notice(me, from.uid, format!("\x02{chan}\x02 is now suspended{expiry}."));
+        }
+        Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+    }
+}
+
+fn now_unix() -> u64 {
+    SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(0)
+}