nickserv: account SUSPEND / UNSUSPEND (oper-gated)

Freezes an account (data kept, login blocked) gated on the typed Priv::Suspend.
A typed Suspension{by,reason,ts,expires} on the account, folded through the
event log (persists, replays, federates) -- no stringly Extensible/Checker like
Anope. Expiry is evaluated lazily at check-time, so there is no expiry timer.
Blocks IDENTIFY and all SASL mechanisms (via one sasl_login gate); logs out any
live sessions on suspend; the login refusal names who/when/why and when it
lifts. Shown in INFO to owner/auspex. Data + full-flow tests.

nickserv/src/suspend.rs

@@ -0,0 +1,67 @@
+use fedserv_api::{NetView, Priv, Sender, ServiceCtx, Store};
+use std::time::{SystemTime, UNIX_EPOCH};
+
+// SUSPEND <account> [+expiry] [reason] / UNSUSPEND <account>: freeze or unfreeze
+// an account. Its data is kept but it can't be logged into. 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(&target) = args.get(1) else {
+        let syntax = if suspending { "Syntax: SUSPEND <account> [+expiry] [reason]" } else { "Syntax: UNSUSPEND <account>" };
+        ctx.notice(me, from.uid, syntax);
+        return;
+    };
+    let Some(account) = db.resolve_account(target).map(str::to_string) else {
+        ctx.notice(me, from.uid, format!("\x02{target}\x02 isn't registered."));
+        return;
+    };
+
+    if !suspending {
+        match db.unsuspend_account(&account) {
+            Ok(true) => ctx.notice(me, from.uid, format!("\x02{account}\x02 is no longer suspended.")),
+            Ok(false) => ctx.notice(me, from.uid, format!("\x02{account}\x02 isn't suspended.")),
+            Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+        }
+        return;
+    }
+
+    // Optional leading +expiry (e.g. +30d), then a free-text reason.
+    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() { "No reason given.".to_string() } else { rest.join(" ") };
+    let by = from.account.unwrap_or(from.nick);
+    match db.suspend_account(&account, by, &reason, expires) {
+        Ok(()) => {
+            // Log out every session currently identified to the account.
+            for uid in net.uids_logged_into(&account) {
+                ctx.logout(&uid);
+            }
+            let expiry = if expires.is_some() { " (with expiry)" } else { "" };
+            ctx.notice(me, from.uid, format!("\x02{account}\x02 is now suspended{expiry}."));
+        }
+        Err(_) => ctx.notice(me, from.uid, "Sorry, that didn't work. Please try again in a moment."),
+    }
+}
+
+// Parse a duration like "30d", "12h", "45m", "90s", or a bare number of seconds.
+fn parse_duration(s: &str) -> Option<u64> {
+    let (num, mult) = match s.chars().last()? {
+        'd' | 'D' => (&s[..s.len() - 1], 86_400),
+        'h' | 'H' => (&s[..s.len() - 1], 3_600),
+        'm' | 'M' => (&s[..s.len() - 1], 60),
+        's' | 'S' => (&s[..s.len() - 1], 1),
+        c if c.is_ascii_digit() => (s, 1),
+        _ => return None,
+    };
+    num.parse::<u64>().ok().map(|n| n * mult)
+}
+
+fn now_unix() -> u64 {
+    SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(0)
+}