NickServ: add SET HIDE STATUS for last-seen privacy

Lets an account keep its last-seen/online line in INFO visible only to
itself and to opers. Default stays public (Anope's default). Accepts
STATUS (with USERMASK as an alias) per Anope's SET HIDE <field> grammar.

src/engine/db/account.rs

@@ -21,7 +21,7 @@ impl Db {
             ajoin: Vec::new(),
             suspension: None,
             memos: Vec::new(), memo_ignore: Vec::new(), memo_notify: true, memo_limit: None,
-            greet: String::new(), no_autoop: false, no_protect: false,
+            greet: String::new(), no_autoop: false, no_protect: false, hide_status: false,
             vhost: None,
             vhost_request: None,
             last_seen: now(),
@@ -60,7 +60,7 @@ impl Db {
             ajoin: Vec::new(),
             suspension: None,
             memos: Vec::new(), memo_ignore: Vec::new(), memo_notify: true, memo_limit: None,
-            greet: String::new(), no_autoop: false, no_protect: false,
+            greet: String::new(), no_autoop: false, no_protect: false, hide_status: false,
             vhost: None,
             vhost_request: None,
             last_seen: now(),
@@ -450,6 +450,22 @@ impl Db {
         self.accounts.get(&key(account)).is_none_or(|a| !a.no_protect)
     }
 
+    /// Set whether `account` hides its last-seen/online line from other users.
+    pub fn set_account_hide_status(&mut self, account: &str, on: bool) -> Result<(), RegError> {
+        let k = key(account);
+        if !self.accounts.contains_key(&k) {
+            return Err(RegError::Internal);
+        }
+        self.log.append(Event::AccountHideStatusSet { account: account.to_string(), on }).map_err(|_| RegError::Internal)?;
+        self.accounts.get_mut(&k).unwrap().hide_status = on;
+        Ok(())
+    }
+
+    /// Whether `account` hides its last-seen/online line from others (default false).
+    pub fn account_hides_status(&self, account: &str) -> bool {
+        self.accounts.get(&key(account)).is_some_and(|a| a.hide_status)
+    }
+
     /// Replace `account`'s password with freshly derived credentials.
     pub fn set_credentials(&mut self, account: &str, creds: Credentials) -> Result<(), RegError> {
         let k = key(account);

src/engine/db/event.rs

@@ -17,6 +17,7 @@ pub enum Event {
     AccountGreetSet { account: String, greet: String },
     AccountAutoOpSet { account: String, on: bool },
     AccountKillSet { account: String, on: bool },
+    AccountHideStatusSet { account: String, on: bool },
     AccountPasswordSet { account: String, scram256: String, scram512: String },
     AccountDropped { account: String },
     AccountVerified { account: String },
@@ -151,6 +152,7 @@ impl Event {
             | Event::AccountGreetSet { .. }
             | Event::AccountAutoOpSet { .. }
             | Event::AccountKillSet { .. }
+            | Event::AccountHideStatusSet { .. }
             | Event::AccountPasswordSet { .. }
             | Event::AccountDropped { .. }
             | Event::AccountVerified { .. }
@@ -287,6 +289,11 @@ pub(crate) fn apply(accounts: &mut HashMap<String, Account>, channels: &mut Hash
                 a.no_protect = !on;
             }
         }
+        Event::AccountHideStatusSet { account, on } => {
+            if let Some(a) = accounts.get_mut(&key(&account)) {
+                a.hide_status = on;
+            }
+        }
         Event::AccountPasswordSet { account, scram256, scram512 } => {
             if let Some(a) = accounts.get_mut(&key(&account)) {
                 a.scram256 = Some(scram256);

src/engine/db/mod.rs

@@ -101,6 +101,11 @@ pub struct Account {
     // inverted so the default (protection enabled) is the zero value.
     #[serde(default)]
     pub no_protect: bool,
+    // NickServ SET HIDE STATUS: when set, the last-seen / online line in INFO is
+    // shown only to the account's owner and to opers, not to other users. Default
+    // (visible) is the zero value.
+    #[serde(default)]
+    pub hide_status: bool,
     // Assigned vhost (HostServ), applied to the displayed host on identify.
     #[serde(default)]
     pub vhost: Option<Vhost>,

src/engine/db/store.rs

@@ -12,6 +12,7 @@ impl Store for Db {
             verified: a.verified,
             greet: a.greet.clone(),
             last_seen: a.last_seen,
+            hide_status: a.hide_status,
         })
     }
     fn resolve_account(&self, name: &str) -> Option<&str> {
@@ -20,7 +21,7 @@ impl Store for Db {
     fn accounts_matching(&self, pattern: &str) -> Vec<AccountView> {
         self.accounts()
             .filter(|a| super::glob_match(pattern, &a.name))
-            .map(|a| AccountView { name: a.name.clone(), email: a.email.clone(), ts: a.ts, verified: a.verified, greet: a.greet.clone(), last_seen: a.last_seen })
+            .map(|a| AccountView { name: a.name.clone(), email: a.email.clone(), ts: a.ts, verified: a.verified, greet: a.greet.clone(), last_seen: a.last_seen, hide_status: a.hide_status })
             .collect()
     }
     fn accounts_by_email(&self, pattern: &str) -> Vec<String> {
@@ -95,6 +96,12 @@ impl Store for Db {
     fn account_wants_protect(&self, account: &str) -> bool {
         Db::account_wants_protect(self, account)
     }
+    fn set_account_hide_status(&mut self, account: &str, on: bool) -> Result<(), RegError> {
+        Db::set_account_hide_status(self, account, on)
+    }
+    fn account_hides_status(&self, account: &str) -> bool {
+        Db::account_hides_status(self, account)
+    }
     fn set_vhost(&mut self, account: &str, host: &str, setter: &str, ttl: Option<u64>) -> Result<(), RegError> {
         Db::set_vhost(self, account, host, setter, ttl)
     }

src/engine/db/tests.rs

@@ -32,7 +32,7 @@
         // which of the two competing registrations we're looking at.
         let alice = |tag: &str, ts: u64, home: &str| Account {
             name: "alice".into(), email: Some(tag.into()),
-            ts, home: home.into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], memo_notify: true, memo_limit: None, greet: String::new(), no_autoop: false, no_protect: false, vhost: None, vhost_request: None, last_seen: ts, noexpire: false, expiry_warned: false, oper_note: None,
+            ts, home: home.into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], memo_notify: true, memo_limit: None, greet: String::new(), no_autoop: false, no_protect: false, hide_status: false, vhost: None, vhost_request: None, last_seen: ts, noexpire: false, expiry_warned: false, oper_note: None,
         };
         let converge = |first: &Account, second: &Account| {
             let (mut acc, mut ch, mut gr, mut bo, mut hc, mut nd) = (HashMap::new(), HashMap::new(), HashMap::new(), HashMap::new(), HostConfig::default(), NetData::default());
@@ -329,7 +329,7 @@
         db.register("alice", "pw", None).unwrap();
         let bob = Account {
             name: "bob".into(), email: None,
-            ts: 0, home: "peer".into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], memo_notify: true, memo_limit: None, greet: String::new(), no_autoop: false, no_protect: false, vhost: None, vhost_request: None, last_seen: 0, noexpire: false, expiry_warned: false, oper_note: None,
+            ts: 0, home: "peer".into(), scram256: None, scram512: None, certfps: vec![], verified: true, ajoin: vec![], suspension: None, memos: vec![], memo_ignore: vec![], memo_notify: true, memo_limit: None, greet: String::new(), no_autoop: false, no_protect: false, hide_status: false, vhost: None, vhost_request: None, last_seen: 0, noexpire: false, expiry_warned: false, oper_note: None,
         };
         let entry = LogEntry { origin: "peer".into(), seq: 0, lamport: 1, event: Event::AccountRegistered(Box::new(bob)) };
         db.ingest(entry).unwrap();