Group the module crates under modules/

The service pseudo-clients and the ircd protocol link sat flat at the
repo root, mixed in with the daemon core and the SDK. Move them all
under modules/ so the tree separates concerns cleanly: the daemon in
src/, the SDK every module links against in api/, and the loadable
modules — the pseudo-clients plus the protocol link — in modules/.

Workspace members, the daemon's per-crate dependency paths, and each
module's api path are updated to match; the docs follow. No code change.

modules/nickserv/src/ghost.rs

@@ -0,0 +1,36 @@
+use fedserv_api::Store;
+use fedserv_api::{Sender, ServiceCtx};
+use fedserv_api::NetView;
+
+// GHOST/RECOVER <nick> [password]: rename off a session using a nick you own,
+// either by being identified to its account or giving that account's password.
+// Every argument is a distinct input the guest-rename needs (the guest nick and
+// its sequence counter among them), so the count is inherent.
+#[allow(clippy::too_many_arguments)]
+pub fn handle(me: &str, guest_nick: &str, guest_seq: &mut u32, from: &Sender, args: &[&str], ctx: &mut ServiceCtx, net: &dyn NetView, db: &dyn Store) {
+    let Some(&target) = args.get(1) else {
+        ctx.notice(me, from.uid, "Syntax: GHOST <nick> [password]");
+        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;
+    };
+    let owns = from.account == Some(account.as_str()) || args.get(2).is_some_and(|pw| db.authenticate(target, pw).is_some());
+    if !owns {
+        ctx.notice(me, from.uid, format!("Access denied. Identify to \x02{account}\x02 or give its password."));
+        return;
+    }
+    let Some(ghost) = net.uid_by_nick(target).map(str::to_string) else {
+        ctx.notice(me, from.uid, format!("Nobody is using \x02{target}\x02."));
+        return;
+    };
+    if ghost == from.uid {
+        ctx.notice(me, from.uid, "That's you.");
+        return;
+    }
+    let guest = format!("{guest_nick}{guest_seq}");
+    *guest_seq = guest_seq.wrapping_add(1);
+    ctx.force_nick(&ghost, &guest);
+    ctx.notice(me, from.uid, format!("\x02{target}\x02 has been freed."));
+}